From: David Zafman <david.zafman@inktank.com>
Date: Fri, 28 Mar 2014 22:07:08 +0000 (-0700)
Subject: test: Add EC testing to ceph_test_rados_api_tier
X-Git-Tag: v0.79~28^2~2
X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=759878c16d5acde6bea0e122e8cf74154986d96e;p=ceph.git

test: Add EC testing to ceph_test_rados_api_tier

Signed-off-by: David Zafman <david.zafman@inktank.com>
---

diff --git a/src/test/librados/tier.cc b/src/test/librados/tier.cc
index 7ec2fab707b48..1543cbd379ffb 100644
--- a/src/test/librados/tier.cc
+++ b/src/test/librados/tier.cc
@@ -32,6 +32,7 @@ using std::ostringstream;
 using std::string;
 
 typedef RadosTestPP LibRadosTierPP;
+typedef RadosTestECPP LibRadosTierECPP;
 
 class LibRadosTwoPoolsPP : public RadosTestPP
 {
@@ -2161,6 +2162,1970 @@ TEST_F(LibRadosTierPP, HitSetTrim) {
   }
 }
 
+class LibRadosTwoPoolsECPP : public RadosTestECPP
+{
+public:
+  LibRadosTwoPoolsECPP() {};
+  virtual ~LibRadosTwoPoolsECPP() {};
+protected:
+  static void SetUpTestCase() {
+    pool_name = get_temp_pool_name();
+    ASSERT_EQ("", create_one_ec_pool_pp(pool_name, s_cluster));
+    cache_pool_name = get_temp_pool_name();
+    ASSERT_EQ(0, s_cluster.pool_create(cache_pool_name.c_str()));
+  }
+  static void TearDownTestCase() {
+    ASSERT_EQ(0, s_cluster.pool_delete(cache_pool_name.c_str()));
+    ASSERT_EQ(0, destroy_one_ec_pool_pp(pool_name, s_cluster));
+  }
+  static std::string cache_pool_name;
+
+  virtual void SetUp() {
+    RadosTestECPP::SetUp();
+    ASSERT_EQ(0, cluster.ioctx_create(cache_pool_name.c_str(), cache_ioctx));
+    cache_ioctx.set_namespace(ns);
+  }
+  virtual void TearDown() {
+    RadosTestECPP::TearDown();
+    cleanup_default_namespace(cache_ioctx);
+    cache_ioctx.close();
+  }
+  librados::IoCtx cache_ioctx;
+};
+
+std::string LibRadosTwoPoolsECPP::cache_pool_name;
+
+TEST_F(LibRadosTierECPP, Dirty) {
+  {
+    ObjectWriteOperation op;
+    op.undirty();
+    ASSERT_EQ(0, ioctx.operate("foo", &op)); // still get 0 if it dne
+  }
+  {
+    ObjectWriteOperation op;
+    op.create(true);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+  {
+    bool dirty = false;
+    int r = -1;
+    ObjectReadOperation op;
+    op.is_dirty(&dirty, &r);
+    ASSERT_EQ(0, ioctx.operate("foo", &op, NULL));
+    ASSERT_TRUE(dirty);
+    ASSERT_EQ(0, r);
+  }
+  {
+    ObjectWriteOperation op;
+    op.undirty();
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+  {
+    ObjectWriteOperation op;
+    op.undirty();
+    ASSERT_EQ(0, ioctx.operate("foo", &op));  // still 0 if already clean
+  }
+  {
+    bool dirty = false;
+    int r = -1;
+    ObjectReadOperation op;
+    op.is_dirty(&dirty, &r);
+    ASSERT_EQ(0, ioctx.operate("foo", &op, NULL));
+    ASSERT_FALSE(dirty);
+    ASSERT_EQ(0, r);
+  }
+  //{
+  //  ObjectWriteOperation op;
+  //  op.truncate(0);  // still a write even tho it is a no-op
+  //  ASSERT_EQ(0, ioctx.operate("foo", &op));
+  //}
+  //{
+  //  bool dirty = false;
+  //  int r = -1;
+  //  ObjectReadOperation op;
+  //  op.is_dirty(&dirty, &r);
+  //  ASSERT_EQ(0, ioctx.operate("foo", &op, NULL));
+  //  ASSERT_TRUE(dirty);
+  //  ASSERT_EQ(0, r);
+  //}
+}
+
+TEST_F(LibRadosTwoPoolsECPP, Overlay) {
+  // create objects
+  {
+    bufferlist bl;
+    bl.append("base");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+  {
+    bufferlist bl;
+    bl.append("cache");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, cache_ioctx.operate("foo", &op));
+  }
+
+  // configure cache
+  bufferlist inbl;
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier add\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name +
+    "\", \"force_nonempty\": \"--force-nonempty\" }",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier set-overlay\", \"pool\": \"" + pool_name +
+    "\", \"overlaypool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle
+  cluster.wait_for_latest_osdmap();
+
+  // by default, the overlay sends us to cache pool
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("foo", bl, 1, 0));
+    ASSERT_EQ('c', bl[0]);
+  }
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, cache_ioctx.read("foo", bl, 1, 0));
+    ASSERT_EQ('c', bl[0]);
+  }
+
+  // unless we say otherwise
+  {
+    bufferlist bl;
+    ObjectReadOperation op;
+    op.read(0, 1, &bl, NULL);
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, ioctx.aio_operate(
+	"foo", completion, &op,
+	librados::OPERATION_IGNORE_OVERLAY, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(0, completion->get_return_value());
+    completion->release();
+    ASSERT_EQ('b', bl[0]);
+  }
+
+  // tear down tiers
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove-overlay\", \"pool\": \"" + pool_name +
+    "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle before next test
+  cluster.wait_for_latest_osdmap();
+}
+
+TEST_F(LibRadosTwoPoolsECPP, Promote) {
+  // create object
+  {
+    bufferlist bl;
+    bl.append("hi there");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+
+  // configure cache
+  bufferlist inbl;
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier add\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name +
+    "\", \"force_nonempty\": \"--force-nonempty\" }",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier set-overlay\", \"pool\": \"" + pool_name +
+    "\", \"overlaypool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier cache-mode\", \"pool\": \"" + cache_pool_name +
+    "\", \"mode\": \"writeback\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle
+  cluster.wait_for_latest_osdmap();
+
+  // read, trigger a promote
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("foo", bl, 1, 0));
+  }
+
+  // read, trigger a whiteout
+  {
+    bufferlist bl;
+    ASSERT_EQ(-ENOENT, ioctx.read("bar", bl, 1, 0));
+    ASSERT_EQ(-ENOENT, ioctx.read("bar", bl, 1, 0));
+  }
+
+  // verify the object is present in the cache tier
+  {
+    ObjectIterator it = cache_ioctx.objects_begin();
+    ASSERT_TRUE(it != cache_ioctx.objects_end());
+    ASSERT_TRUE(it->first == string("foo") || it->first == string("bar"));
+    ++it;
+    ASSERT_TRUE(it->first == string("foo") || it->first == string("bar"));
+    ++it;
+    ASSERT_TRUE(it == cache_ioctx.objects_end());
+  }
+
+  // tear down tiers
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove-overlay\", \"pool\": \"" + pool_name +
+    "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle before next test
+  cluster.wait_for_latest_osdmap();
+}
+
+TEST_F(LibRadosTwoPoolsECPP, PromoteSnap) {
+  // create object
+  {
+    bufferlist bl;
+    bl.append("hi there");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+  {
+    bufferlist bl;
+    bl.append("hi there");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("bar", &op));
+  }
+  {
+    bufferlist bl;
+    bl.append("hi there");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("baz", &op));
+  }
+  {
+    bufferlist bl;
+    bl.append("hi there");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("bam", &op));
+  }
+
+  // create a snapshot, clone
+  vector<uint64_t> my_snaps(1);
+  ASSERT_EQ(0, ioctx.selfmanaged_snap_create(&my_snaps[0]));
+  ASSERT_EQ(0, ioctx.selfmanaged_snap_set_write_ctx(my_snaps[0],
+							 my_snaps));
+  {
+    bufferlist bl;
+    bl.append("ciao!");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+  {
+    bufferlist bl;
+    bl.append("ciao!");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("bar", &op));
+  }
+  {
+    ObjectWriteOperation op;
+    op.remove();
+    ASSERT_EQ(0, ioctx.operate("baz", &op));
+  }
+  {
+    bufferlist bl;
+    bl.append("ciao!");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("bam", &op));
+  }
+
+  // configure cache
+  bufferlist inbl;
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier add\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name +
+    "\", \"force_nonempty\": \"--force-nonempty\" }",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier set-overlay\", \"pool\": \"" + pool_name +
+    "\", \"overlaypool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier cache-mode\", \"pool\": \"" + cache_pool_name +
+    "\", \"mode\": \"writeback\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle
+  cluster.wait_for_latest_osdmap();
+
+  // read, trigger a promote on the head
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("foo", bl, 1, 0));
+    ASSERT_EQ('c', bl[0]);
+  }
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("bam", bl, 1, 0));
+    ASSERT_EQ('c', bl[0]);
+  }
+
+  ioctx.snap_set_read(my_snaps[0]);
+
+  // stop and scrub this pg (to make sure scrub can handle missing
+  // clones in the cache tier)
+  // This test requires cache tier and base tier to have the same pg_num/pgp_num
+  {
+    IoCtx cache_ioctx;
+    ASSERT_EQ(0, cluster.ioctx_create(cache_pool_name.c_str(), cache_ioctx));
+    ostringstream ss;
+    ss << "{\"prefix\": \"pg scrub\", \"pgid\": \""
+       << cache_ioctx.get_id() << "."
+       << ioctx.get_object_pg_hash_position("foo")
+       << "\"}";
+    ASSERT_EQ(0, cluster.mon_command(ss.str(), inbl, NULL, NULL));
+
+    // give it a few seconds to go.  this is sloppy but is usually enough time
+    cout << "waiting for scrub..." << std::endl;
+    sleep(15);
+    cout << "done waiting" << std::endl;
+  }
+
+  // read foo snap
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("foo", bl, 1, 0));
+    ASSERT_EQ('h', bl[0]);
+  }
+
+  // read bar snap
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("bar", bl, 1, 0));
+    ASSERT_EQ('h', bl[0]);
+  }
+
+  // read baz snap
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("baz", bl, 1, 0));
+    ASSERT_EQ('h', bl[0]);
+  }
+
+  ioctx.snap_set_read(librados::SNAP_HEAD);
+
+  // read foo
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("foo", bl, 1, 0));
+    ASSERT_EQ('c', bl[0]);
+  }
+
+  // read bar
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("bar", bl, 1, 0));
+    ASSERT_EQ('c', bl[0]);
+  }
+
+  // read baz
+  {
+    bufferlist bl;
+    ASSERT_EQ(-ENOENT, ioctx.read("baz", bl, 1, 0));
+  }
+
+  // tear down tiers
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove-overlay\", \"pool\": \"" + pool_name +
+    "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle before next test
+  cluster.wait_for_latest_osdmap();
+}
+
+TEST_F(LibRadosTwoPoolsECPP, PromoteSnapTrimRace) {
+  // create object
+  {
+    bufferlist bl;
+    bl.append("hi there");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+
+  // create a snapshot, clone
+  vector<uint64_t> my_snaps(1);
+  ASSERT_EQ(0, ioctx.selfmanaged_snap_create(&my_snaps[0]));
+  ASSERT_EQ(0, ioctx.selfmanaged_snap_set_write_ctx(my_snaps[0],
+							 my_snaps));
+  {
+    bufferlist bl;
+    bl.append("ciao!");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+
+  // configure cache
+  bufferlist inbl;
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier add\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name +
+    "\", \"force_nonempty\": \"--force-nonempty\" }",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier set-overlay\", \"pool\": \"" + pool_name +
+    "\", \"overlaypool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier cache-mode\", \"pool\": \"" + cache_pool_name +
+    "\", \"mode\": \"writeback\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle
+  cluster.wait_for_latest_osdmap();
+
+  // delete the snap
+  ASSERT_EQ(0, ioctx.selfmanaged_snap_remove(my_snaps[0]));
+
+  ioctx.snap_set_read(my_snaps[0]);
+
+  // read foo snap
+  {
+    bufferlist bl;
+    ASSERT_EQ(-ENOENT, ioctx.read("foo", bl, 1, 0));
+  }
+
+  // tear down tiers
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove-overlay\", \"pool\": \"" + pool_name +
+    "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle before next test
+  cluster.wait_for_latest_osdmap();
+}
+
+TEST_F(LibRadosTwoPoolsECPP, Whiteout) {
+  // create object
+  {
+    bufferlist bl;
+    bl.append("hi there");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+
+  // configure cache
+  bufferlist inbl;
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier add\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name +
+    "\", \"force_nonempty\": \"--force-nonempty\" }",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier set-overlay\", \"pool\": \"" + pool_name +
+    "\", \"overlaypool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier cache-mode\", \"pool\": \"" + cache_pool_name +
+    "\", \"mode\": \"writeback\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle
+  cluster.wait_for_latest_osdmap();
+
+  // create some whiteouts, verify they behave
+  ASSERT_EQ(0, ioctx.remove("foo"));
+
+  ASSERT_EQ(-ENOENT, ioctx.remove("bar"));
+  ASSERT_EQ(-ENOENT, ioctx.remove("bar"));
+
+  // verify the whiteouts are there in the cache tier
+  {
+    ObjectIterator it = cache_ioctx.objects_begin();
+    ASSERT_TRUE(it != cache_ioctx.objects_end());
+    ASSERT_TRUE(it->first == string("foo") || it->first == string("bar"));
+    ++it;
+    ASSERT_TRUE(it->first == string("foo") || it->first == string("bar"));
+    ++it;
+    ASSERT_TRUE(it == cache_ioctx.objects_end());
+  }
+
+  ASSERT_EQ(-ENOENT, ioctx.remove("foo"));
+
+  // recreate an object and verify we can read it
+  {
+    bufferlist bl;
+    bl.append("hi there");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("foo", bl, 1, 0));
+    ASSERT_EQ('h', bl[0]);
+  }
+
+  // tear down tiers
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove-overlay\", \"pool\": \"" + pool_name +
+    "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle before next test
+  cluster.wait_for_latest_osdmap();
+}
+
+TEST_F(LibRadosTwoPoolsECPP, Evict) {
+  // create object
+  {
+    bufferlist bl;
+    bl.append("hi there");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+
+  // configure cache
+  bufferlist inbl;
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier add\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name +
+    "\", \"force_nonempty\": \"--force-nonempty\" }",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier set-overlay\", \"pool\": \"" + pool_name +
+    "\", \"overlaypool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier cache-mode\", \"pool\": \"" + cache_pool_name +
+    "\", \"mode\": \"writeback\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle
+  cluster.wait_for_latest_osdmap();
+
+  // read, trigger a promote
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("foo", bl, 1, 0));
+  }
+
+  // read, trigger a whiteout, and a dirty object
+  {
+    bufferlist bl;
+    ASSERT_EQ(-ENOENT, ioctx.read("bar", bl, 1, 0));
+    ASSERT_EQ(-ENOENT, ioctx.read("bar", bl, 1, 0));
+    ASSERT_EQ(0, ioctx.write("bar", bl, bl.length(), 0));
+  }
+
+  // verify the object is present in the cache tier
+  {
+    ObjectIterator it = cache_ioctx.objects_begin();
+    ASSERT_TRUE(it != cache_ioctx.objects_end());
+    ASSERT_TRUE(it->first == string("foo") || it->first == string("bar"));
+    ++it;
+    ASSERT_TRUE(it->first == string("foo") || it->first == string("bar"));
+    ++it;
+    ASSERT_TRUE(it == cache_ioctx.objects_end());
+  }
+
+  // evict
+  {
+    ObjectReadOperation op;
+    op.cache_evict();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, cache_ioctx.aio_operate("foo", completion, &op,
+					 librados::OPERATION_IGNORE_CACHE,
+					 NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(0, completion->get_return_value());
+    completion->release();
+  }
+  {
+    ObjectReadOperation op;
+    op.cache_evict();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, cache_ioctx.aio_operate(
+      "fooberdoodle", completion, &op,
+      librados::OPERATION_IGNORE_CACHE, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(-ENOENT, completion->get_return_value());
+    completion->release();
+  }
+  {
+    ObjectReadOperation op;
+    op.cache_evict();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, cache_ioctx.aio_operate(
+      "bar", completion, &op,
+      librados::OPERATION_IGNORE_CACHE, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(-EBUSY, completion->get_return_value());
+    completion->release();
+  }
+
+  // tear down tiers
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove-overlay\", \"pool\": \"" + pool_name +
+    "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle before next test
+  cluster.wait_for_latest_osdmap();
+}
+
+TEST_F(LibRadosTwoPoolsECPP, EvictSnap) {
+  // create object
+  {
+    bufferlist bl;
+    bl.append("hi there");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+  {
+    bufferlist bl;
+    bl.append("hi there");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("bar", &op));
+  }
+  {
+    bufferlist bl;
+    bl.append("hi there");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("baz", &op));
+  }
+  {
+    bufferlist bl;
+    bl.append("hi there");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("bam", &op));
+  }
+
+  // create a snapshot, clone
+  vector<uint64_t> my_snaps(1);
+  ASSERT_EQ(0, ioctx.selfmanaged_snap_create(&my_snaps[0]));
+  ASSERT_EQ(0, ioctx.selfmanaged_snap_set_write_ctx(my_snaps[0],
+							 my_snaps));
+  {
+    bufferlist bl;
+    bl.append("ciao!");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+  {
+    bufferlist bl;
+    bl.append("ciao!");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("bar", &op));
+  }
+  {
+    ObjectWriteOperation op;
+    op.remove();
+    ASSERT_EQ(0, ioctx.operate("baz", &op));
+  }
+  {
+    bufferlist bl;
+    bl.append("ciao!");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("bam", &op));
+  }
+
+  // configure cache
+  bufferlist inbl;
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier add\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name +
+    "\", \"force_nonempty\": \"--force-nonempty\" }",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier set-overlay\", \"pool\": \"" + pool_name +
+    "\", \"overlaypool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier cache-mode\", \"pool\": \"" + cache_pool_name +
+    "\", \"mode\": \"writeback\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle
+  cluster.wait_for_latest_osdmap();
+
+  // read, trigger a promote on the head
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("foo", bl, 1, 0));
+    ASSERT_EQ('c', bl[0]);
+  }
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("bam", bl, 1, 0));
+    ASSERT_EQ('c', bl[0]);
+  }
+
+  // evict bam
+  {
+    ObjectReadOperation op;
+    op.cache_evict();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, cache_ioctx.aio_operate(
+      "bam", completion, &op,
+      librados::OPERATION_IGNORE_CACHE, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(0, completion->get_return_value());
+    completion->release();
+  }
+  {
+    bufferlist bl;
+    ObjectReadOperation op;
+    op.read(1, 0, &bl, NULL);
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, cache_ioctx.aio_operate(
+      "bam", completion, &op,
+      librados::OPERATION_IGNORE_CACHE, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(-ENOENT, completion->get_return_value());
+    completion->release();
+  }
+
+  // read foo snap
+  ioctx.snap_set_read(my_snaps[0]);
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("foo", bl, 1, 0));
+    ASSERT_EQ('h', bl[0]);
+  }
+
+  // evict foo snap
+  {
+    ObjectReadOperation op;
+    op.cache_evict();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, ioctx.aio_operate(
+      "foo", completion, &op,
+      librados::OPERATION_IGNORE_CACHE, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(0, completion->get_return_value());
+    completion->release();
+  }
+  // snap is gone...
+  {
+    bufferlist bl;
+    ObjectReadOperation op;
+    op.read(1, 0, &bl, NULL);
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, ioctx.aio_operate(
+      "foo", completion, &op,
+      librados::OPERATION_IGNORE_CACHE, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(-ENOENT, completion->get_return_value());
+    completion->release();
+  }
+  // head is still there...
+  ioctx.snap_set_read(librados::SNAP_HEAD);
+  {
+    bufferlist bl;
+    ObjectReadOperation op;
+    op.read(1, 0, &bl, NULL);
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, ioctx.aio_operate(
+      "foo", completion, &op,
+      librados::OPERATION_IGNORE_CACHE, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(0, completion->get_return_value());
+    completion->release();
+  }
+
+  // promote head + snap of bar
+  ioctx.snap_set_read(librados::SNAP_HEAD);
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("bar", bl, 1, 0));
+    ASSERT_EQ('c', bl[0]);
+  }
+  ioctx.snap_set_read(my_snaps[0]);
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("bar", bl, 1, 0));
+    ASSERT_EQ('h', bl[0]);
+  }
+
+  // evict bar head (fail)
+  ioctx.snap_set_read(librados::SNAP_HEAD);
+  {
+    ObjectReadOperation op;
+    op.cache_evict();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, ioctx.aio_operate(
+      "bar", completion, &op,
+      librados::OPERATION_IGNORE_CACHE, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(-EBUSY, completion->get_return_value());
+    completion->release();
+  }
+
+  // evict bar snap
+  ioctx.snap_set_read(my_snaps[0]);
+  {
+    ObjectReadOperation op;
+    op.cache_evict();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, ioctx.aio_operate(
+      "bar", completion, &op,
+      librados::OPERATION_IGNORE_CACHE, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(0, completion->get_return_value());
+    completion->release();
+  }
+  // ...and then head
+  ioctx.snap_set_read(librados::SNAP_HEAD);
+  {
+    bufferlist bl;
+    ObjectReadOperation op;
+    op.read(1, 0, &bl, NULL);
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, ioctx.aio_operate(
+      "bar", completion, &op,
+      librados::OPERATION_IGNORE_CACHE, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(0, completion->get_return_value());
+    completion->release();
+  }
+  {
+    ObjectReadOperation op;
+    op.cache_evict();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, ioctx.aio_operate(
+      "bar", completion, &op,
+      librados::OPERATION_IGNORE_CACHE, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(0, completion->get_return_value());
+    completion->release();
+  }
+
+  // tear down tiers
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove-overlay\", \"pool\": \"" + pool_name +
+    "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle before next test
+  cluster.wait_for_latest_osdmap();
+}
+
+TEST_F(LibRadosTwoPoolsECPP, TryFlush) {
+  // configure cache
+  bufferlist inbl;
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier add\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name +
+    "\", \"force_nonempty\": \"--force-nonempty\" }",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier set-overlay\", \"pool\": \"" + pool_name +
+    "\", \"overlaypool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier cache-mode\", \"pool\": \"" + cache_pool_name +
+    "\", \"mode\": \"writeback\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle
+  cluster.wait_for_latest_osdmap();
+
+  // create object
+  {
+    bufferlist bl;
+    bl.append("hi there");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+
+  // verify the object is present in the cache tier
+  {
+    ObjectIterator it = cache_ioctx.objects_begin();
+    ASSERT_TRUE(it != cache_ioctx.objects_end());
+    ASSERT_TRUE(it->first == string("foo"));
+    ++it;
+    ASSERT_TRUE(it == cache_ioctx.objects_end());
+  }
+
+  // verify the object is NOT present in the base tier
+  {
+    ObjectIterator it = ioctx.objects_begin();
+    ASSERT_TRUE(it == ioctx.objects_end());
+  }
+
+  // verify dirty
+  {
+    bool dirty = false;
+    int r = -1;
+    ObjectReadOperation op;
+    op.is_dirty(&dirty, &r);
+    ASSERT_EQ(0, cache_ioctx.operate("foo", &op, NULL));
+    ASSERT_TRUE(dirty);
+    ASSERT_EQ(0, r);
+  }
+
+  // flush
+  {
+    ObjectReadOperation op;
+    op.cache_try_flush();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, cache_ioctx.aio_operate(
+      "foo", completion, &op,
+      librados::OPERATION_IGNORE_OVERLAY |
+      librados::OPERATION_SKIPRWLOCKS, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(0, completion->get_return_value());
+    completion->release();
+  }
+
+  // verify clean
+  {
+    bool dirty = false;
+    int r = -1;
+    ObjectReadOperation op;
+    op.is_dirty(&dirty, &r);
+    ASSERT_EQ(0, cache_ioctx.operate("foo", &op, NULL));
+    ASSERT_FALSE(dirty);
+    ASSERT_EQ(0, r);
+  }
+
+  // verify in base tier
+  {
+    ObjectIterator it = ioctx.objects_begin();
+    ASSERT_TRUE(it != ioctx.objects_end());
+    ASSERT_TRUE(it->first == string("foo"));
+    ++it;
+    ASSERT_TRUE(it == ioctx.objects_end());
+  }
+
+  // evict it
+  {
+    ObjectReadOperation op;
+    op.cache_evict();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, cache_ioctx.aio_operate(
+	 "foo", completion, &op, librados::OPERATION_IGNORE_CACHE, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(0, completion->get_return_value());
+    completion->release();
+  }
+
+  // verify no longer in cache tier
+  {
+    ObjectIterator it = cache_ioctx.objects_begin();
+    ASSERT_TRUE(it == cache_ioctx.objects_end());
+  }
+
+  // tear down tiers
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove-overlay\", \"pool\": \"" + pool_name +
+    "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle before next test
+  cluster.wait_for_latest_osdmap();
+}
+
+TEST_F(LibRadosTwoPoolsECPP, Flush) {
+  // configure cache
+  bufferlist inbl;
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier add\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name +
+    "\", \"force_nonempty\": \"--force-nonempty\" }",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier set-overlay\", \"pool\": \"" + pool_name +
+    "\", \"overlaypool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier cache-mode\", \"pool\": \"" + cache_pool_name +
+    "\", \"mode\": \"writeback\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle
+  cluster.wait_for_latest_osdmap();
+
+  uint64_t user_version = 0;
+
+  // create object
+  {
+    bufferlist bl;
+    bl.append("hi there");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+
+  // verify the object is present in the cache tier
+  {
+    ObjectIterator it = cache_ioctx.objects_begin();
+    ASSERT_TRUE(it != cache_ioctx.objects_end());
+    ASSERT_TRUE(it->first == string("foo"));
+    ++it;
+    ASSERT_TRUE(it == cache_ioctx.objects_end());
+  }
+
+  // verify the object is NOT present in the base tier
+  {
+    ObjectIterator it = ioctx.objects_begin();
+    ASSERT_TRUE(it == ioctx.objects_end());
+  }
+
+  // verify dirty
+  {
+    bool dirty = false;
+    int r = -1;
+    ObjectReadOperation op;
+    op.is_dirty(&dirty, &r);
+    ASSERT_EQ(0, cache_ioctx.operate("foo", &op, NULL));
+    ASSERT_TRUE(dirty);
+    ASSERT_EQ(0, r);
+    user_version = cache_ioctx.get_last_version();
+  }
+
+  // flush
+  {
+    ObjectReadOperation op;
+    op.cache_flush();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, cache_ioctx.aio_operate(
+      "foo", completion, &op,
+      librados::OPERATION_IGNORE_OVERLAY, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(0, completion->get_return_value());
+    completion->release();
+  }
+
+  // verify clean
+  {
+    bool dirty = false;
+    int r = -1;
+    ObjectReadOperation op;
+    op.is_dirty(&dirty, &r);
+    ASSERT_EQ(0, cache_ioctx.operate("foo", &op, NULL));
+    ASSERT_FALSE(dirty);
+    ASSERT_EQ(0, r);
+  }
+
+  // verify in base tier
+  {
+    ObjectIterator it = ioctx.objects_begin();
+    ASSERT_TRUE(it != ioctx.objects_end());
+    ASSERT_TRUE(it->first == string("foo"));
+    ++it;
+    ASSERT_TRUE(it == ioctx.objects_end());
+  }
+
+  // evict it
+  {
+    ObjectReadOperation op;
+    op.cache_evict();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, cache_ioctx.aio_operate(
+	 "foo", completion, &op, librados::OPERATION_IGNORE_CACHE, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(0, completion->get_return_value());
+    completion->release();
+  }
+
+  // verify no longer in cache tier
+  {
+    ObjectIterator it = cache_ioctx.objects_begin();
+    ASSERT_TRUE(it == cache_ioctx.objects_end());
+  }
+
+  // read it again and verify the version is consistent
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, cache_ioctx.read("foo", bl, 1, 0));
+    ASSERT_EQ(user_version, cache_ioctx.get_last_version());
+  }
+
+  // erase it
+  {
+    ObjectWriteOperation op;
+    op.remove();
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+
+  // flush whiteout
+  {
+    ObjectReadOperation op;
+    op.cache_flush();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, cache_ioctx.aio_operate(
+      "foo", completion, &op,
+      librados::OPERATION_IGNORE_OVERLAY, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(0, completion->get_return_value());
+    completion->release();
+  }
+
+  // evict
+  {
+    ObjectReadOperation op;
+    op.cache_evict();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, cache_ioctx.aio_operate(
+	 "foo", completion, &op, librados::OPERATION_IGNORE_CACHE, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(0, completion->get_return_value());
+    completion->release();
+  }
+
+  // verify no longer in cache tier
+  {
+    ObjectIterator it = cache_ioctx.objects_begin();
+    ASSERT_TRUE(it == cache_ioctx.objects_end());
+  }
+  // or base tier
+  {
+    ObjectIterator it = ioctx.objects_begin();
+    ASSERT_TRUE(it == ioctx.objects_end());
+  }
+
+  // tear down tiers
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove-overlay\", \"pool\": \"" + pool_name +
+    "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle before next test
+  cluster.wait_for_latest_osdmap();
+}
+
+TEST_F(LibRadosTwoPoolsECPP, FlushSnap) {
+  // configure cache
+  bufferlist inbl;
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier add\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name +
+    "\", \"force_nonempty\": \"--force-nonempty\" }",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier set-overlay\", \"pool\": \"" + pool_name +
+    "\", \"overlaypool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier cache-mode\", \"pool\": \"" + cache_pool_name +
+    "\", \"mode\": \"writeback\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle
+  cluster.wait_for_latest_osdmap();
+
+  // create object
+  {
+    bufferlist bl;
+    bl.append("a");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+
+  // create a snapshot, clone
+  vector<uint64_t> my_snaps(1);
+  ASSERT_EQ(0, ioctx.selfmanaged_snap_create(&my_snaps[0]));
+  ASSERT_EQ(0, ioctx.selfmanaged_snap_set_write_ctx(my_snaps[0],
+							 my_snaps));
+  {
+    bufferlist bl;
+    bl.append("b");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+
+  // and another
+  my_snaps.resize(2);
+  my_snaps[1] = my_snaps[0];
+  ASSERT_EQ(0, ioctx.selfmanaged_snap_create(&my_snaps[0]));
+  ASSERT_EQ(0, ioctx.selfmanaged_snap_set_write_ctx(my_snaps[0],
+							 my_snaps));
+  {
+    bufferlist bl;
+    bl.append("c");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+
+  // verify the object is present in the cache tier
+  {
+    ObjectIterator it = cache_ioctx.objects_begin();
+    ASSERT_TRUE(it != cache_ioctx.objects_end());
+    ASSERT_TRUE(it->first == string("foo"));
+    ++it;
+    ASSERT_TRUE(it == cache_ioctx.objects_end());
+  }
+
+  // verify the object is NOT present in the base tier
+  {
+    ObjectIterator it = ioctx.objects_begin();
+    ASSERT_TRUE(it == ioctx.objects_end());
+  }
+
+  // flush on head (should fail)
+  ioctx.snap_set_read(librados::SNAP_HEAD);
+  {
+    ObjectReadOperation op;
+    op.cache_flush();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, ioctx.aio_operate(
+      "foo", completion, &op,
+      librados::OPERATION_IGNORE_CACHE, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(-EBUSY, completion->get_return_value());
+    completion->release();
+  }
+  // flush on recent snap (should fail)
+  ioctx.snap_set_read(my_snaps[0]);
+  {
+    ObjectReadOperation op;
+    op.cache_flush();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, ioctx.aio_operate(
+      "foo", completion, &op,
+      librados::OPERATION_IGNORE_CACHE, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(-EBUSY, completion->get_return_value());
+    completion->release();
+  }
+  // flush on oldest snap
+  ioctx.snap_set_read(my_snaps[1]);
+  {
+    ObjectReadOperation op;
+    op.cache_flush();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, ioctx.aio_operate(
+      "foo", completion, &op,
+      librados::OPERATION_IGNORE_CACHE, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(0, completion->get_return_value());
+    completion->release();
+  }
+  // flush on next oldest snap
+  ioctx.snap_set_read(my_snaps[0]);
+  {
+    ObjectReadOperation op;
+    op.cache_flush();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, ioctx.aio_operate(
+      "foo", completion, &op,
+      librados::OPERATION_IGNORE_CACHE, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(0, completion->get_return_value());
+    completion->release();
+  }
+  // flush on head
+  ioctx.snap_set_read(librados::SNAP_HEAD);
+  {
+    ObjectReadOperation op;
+    op.cache_flush();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, ioctx.aio_operate(
+      "foo", completion, &op,
+      librados::OPERATION_IGNORE_CACHE, NULL));
+    completion->wait_for_safe();
+    ASSERT_EQ(0, completion->get_return_value());
+    completion->release();
+  }
+
+  // verify i can read the snaps from the cache pool
+  ioctx.snap_set_read(librados::SNAP_HEAD);
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("foo", bl, 1, 0));
+    ASSERT_EQ('c', bl[0]);
+  }
+  ioctx.snap_set_read(my_snaps[0]);
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("foo", bl, 1, 0));
+    ASSERT_EQ('b', bl[0]);
+  }
+  ioctx.snap_set_read(my_snaps[1]);
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("foo", bl, 1, 0));
+    ASSERT_EQ('a', bl[0]);
+  }
+
+  // tear down tiers
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove-overlay\", \"pool\": \"" + pool_name +
+    "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle
+  cluster.wait_for_latest_osdmap();
+
+  // verify i can read the snaps from the base pool
+  ioctx.snap_set_read(librados::SNAP_HEAD);
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("foo", bl, 1, 0));
+    ASSERT_EQ('c', bl[0]);
+  }
+  ioctx.snap_set_read(my_snaps[0]);
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("foo", bl, 1, 0));
+    ASSERT_EQ('b', bl[0]);
+  }
+  ioctx.snap_set_read(my_snaps[1]);
+  {
+    bufferlist bl;
+    ASSERT_EQ(1, ioctx.read("foo", bl, 1, 0));
+    ASSERT_EQ('a', bl[0]);
+  }
+}
+
+TEST_F(LibRadosTierECPP, FlushWriteRaces) {
+  Rados cluster;
+  std::string pool_name = get_temp_pool_name();
+  std::string cache_pool_name = pool_name + "-cache";
+  ASSERT_EQ("", create_one_pool_pp(pool_name, cluster));
+  ASSERT_EQ(0, cluster.pool_create(cache_pool_name.c_str()));
+  IoCtx cache_ioctx;
+  ASSERT_EQ(0, cluster.ioctx_create(cache_pool_name.c_str(), cache_ioctx));
+  IoCtx ioctx;
+  ASSERT_EQ(0, cluster.ioctx_create(pool_name.c_str(), ioctx));
+
+  // configure cache
+  bufferlist inbl;
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier add\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier set-overlay\", \"pool\": \"" + pool_name +
+    "\", \"overlaypool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier cache-mode\", \"pool\": \"" + cache_pool_name +
+    "\", \"mode\": \"writeback\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle
+  cluster.wait_for_latest_osdmap();
+
+  // create/dirty object
+  bufferlist bl;
+  bl.append("hi there");
+  {
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+
+  // flush + write
+  {
+    ObjectReadOperation op;
+    op.cache_flush();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, cache_ioctx.aio_operate(
+      "foo", completion, &op,
+      librados::OPERATION_IGNORE_OVERLAY, NULL));
+
+    ObjectWriteOperation op2;
+    op2.write_full(bl);
+    librados::AioCompletion *completion2 = cluster.aio_create_completion();
+    ASSERT_EQ(0, ioctx.aio_operate(
+      "foo", completion2, &op2, 0));
+
+    completion->wait_for_safe();
+    completion2->wait_for_safe();
+    ASSERT_EQ(0, completion->get_return_value());
+    ASSERT_EQ(0, completion2->get_return_value());
+    completion->release();
+    completion2->release();
+  }
+
+  int tries = 1000;
+  do {
+    // create/dirty object
+    {
+      bufferlist bl;
+      bl.append("hi there");
+      ObjectWriteOperation op;
+      op.write_full(bl);
+      ASSERT_EQ(0, ioctx.operate("foo", &op));
+    }
+
+    // try-flush + write
+    {
+      ObjectReadOperation op;
+      op.cache_try_flush();
+      librados::AioCompletion *completion = cluster.aio_create_completion();
+      ASSERT_EQ(0, cache_ioctx.aio_operate(
+        "foo", completion, &op,
+	librados::OPERATION_IGNORE_OVERLAY |
+	librados::OPERATION_SKIPRWLOCKS, NULL));
+
+      ObjectWriteOperation op2;
+      op2.write_full(bl);
+      librados::AioCompletion *completion2 = cluster.aio_create_completion();
+      ASSERT_EQ(0, ioctx.aio_operate("foo", completion2, &op2, 0));
+
+      completion->wait_for_safe();
+      completion2->wait_for_safe();
+      int r = completion->get_return_value();
+      ASSERT_TRUE(r == -EBUSY || r == 0);
+      ASSERT_EQ(0, completion2->get_return_value());
+      completion->release();
+      completion2->release();
+      if (r == -EBUSY)
+	break;
+      cout << "didn't get EBUSY, trying again" << std::endl;
+    }
+    ASSERT_TRUE(--tries);
+  } while (true);
+
+  // tear down tiers
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove-overlay\", \"pool\": \"" + pool_name +
+    "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle before next test
+  cluster.wait_for_latest_osdmap();
+
+  ASSERT_EQ(0, cluster.pool_delete(cache_pool_name.c_str()));
+  ASSERT_EQ(0, destroy_one_pool_pp(pool_name, cluster));
+}
+
+TEST_F(LibRadosTwoPoolsECPP, FlushTryFlushRaces) {
+  // configure cache
+  bufferlist inbl;
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier add\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name +
+    "\", \"force_nonempty\": \"--force-nonempty\" }",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier set-overlay\", \"pool\": \"" + pool_name +
+    "\", \"overlaypool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier cache-mode\", \"pool\": \"" + cache_pool_name +
+    "\", \"mode\": \"writeback\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle
+  cluster.wait_for_latest_osdmap();
+
+  // create/dirty object
+  {
+    bufferlist bl;
+    bl.append("hi there");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+
+  // flush + flush
+  {
+    ObjectReadOperation op;
+    op.cache_flush();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, cache_ioctx.aio_operate(
+      "foo", completion, &op,
+      librados::OPERATION_IGNORE_OVERLAY, NULL));
+
+    ObjectReadOperation op2;
+    op2.cache_flush();
+    librados::AioCompletion *completion2 = cluster.aio_create_completion();
+    ASSERT_EQ(0, cache_ioctx.aio_operate(
+      "foo", completion2, &op2,
+      librados::OPERATION_IGNORE_OVERLAY, NULL));
+
+    completion->wait_for_safe();
+    completion2->wait_for_safe();
+    ASSERT_EQ(0, completion->get_return_value());
+    ASSERT_EQ(0, completion2->get_return_value());
+    completion->release();
+    completion2->release();
+  }
+
+  // create/dirty object
+  {
+    bufferlist bl;
+    bl.append("hi there");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+
+  // flush + try-flush
+  {
+    ObjectReadOperation op;
+    op.cache_flush();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, cache_ioctx.aio_operate(
+      "foo", completion, &op,
+      librados::OPERATION_IGNORE_OVERLAY, NULL));
+
+    ObjectReadOperation op2;
+    op2.cache_try_flush();
+    librados::AioCompletion *completion2 = cluster.aio_create_completion();
+    ASSERT_EQ(0, cache_ioctx.aio_operate(
+      "foo", completion2, &op2,
+      librados::OPERATION_IGNORE_OVERLAY |
+      librados::OPERATION_SKIPRWLOCKS, NULL));
+
+    completion->wait_for_safe();
+    completion2->wait_for_safe();
+    ASSERT_EQ(0, completion->get_return_value());
+    ASSERT_EQ(0, completion2->get_return_value());
+    completion->release();
+    completion2->release();
+  }
+
+  // create/dirty object
+  int tries = 1000;
+  do {
+    {
+      bufferlist bl;
+      bl.append("hi there");
+      ObjectWriteOperation op;
+      op.write_full(bl);
+      ASSERT_EQ(0, ioctx.operate("foo", &op));
+    }
+
+    // try-flush + flush
+    //  (flush will not piggyback on try-flush)
+    {
+      ObjectReadOperation op;
+      op.cache_try_flush();
+      librados::AioCompletion *completion = cluster.aio_create_completion();
+      ASSERT_EQ(0, cache_ioctx.aio_operate(
+        "foo", completion, &op,
+	librados::OPERATION_IGNORE_OVERLAY |
+	librados::OPERATION_SKIPRWLOCKS, NULL));
+
+      ObjectReadOperation op2;
+      op2.cache_flush();
+      librados::AioCompletion *completion2 = cluster.aio_create_completion();
+      ASSERT_EQ(0, cache_ioctx.aio_operate(
+        "foo", completion2, &op2,
+	librados::OPERATION_IGNORE_OVERLAY, NULL));
+
+      completion->wait_for_safe();
+      completion2->wait_for_safe();
+      int r = completion->get_return_value();
+      ASSERT_TRUE(r == -EBUSY || r == 0);
+      ASSERT_EQ(0, completion2->get_return_value());
+      completion->release();
+      completion2->release();
+      if (r == -EBUSY)
+	break;
+      cout << "didn't get EBUSY, trying again" << std::endl;
+    }
+    ASSERT_TRUE(--tries);
+  } while (true);
+
+  // create/dirty object
+  {
+    bufferlist bl;
+    bl.append("hi there");
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+
+  // try-flush + try-flush
+  {
+    ObjectReadOperation op;
+    op.cache_try_flush();
+    librados::AioCompletion *completion = cluster.aio_create_completion();
+    ASSERT_EQ(0, cache_ioctx.aio_operate(
+      "foo", completion, &op,
+      librados::OPERATION_IGNORE_OVERLAY |
+      librados::OPERATION_SKIPRWLOCKS, NULL));
+
+    ObjectReadOperation op2;
+    op2.cache_try_flush();
+    librados::AioCompletion *completion2 = cluster.aio_create_completion();
+    ASSERT_EQ(0, cache_ioctx.aio_operate(
+      "foo", completion2, &op2,
+      librados::OPERATION_IGNORE_OVERLAY |
+      librados::OPERATION_SKIPRWLOCKS, NULL));
+
+    completion->wait_for_safe();
+    completion2->wait_for_safe();
+    ASSERT_EQ(0, completion->get_return_value());
+    ASSERT_EQ(0, completion2->get_return_value());
+    completion->release();
+    completion2->release();
+  }
+
+  // tear down tiers
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove-overlay\", \"pool\": \"" + pool_name +
+    "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle before next test
+  cluster.wait_for_latest_osdmap();
+}
+
+TEST_F(LibRadosTwoPoolsECPP, TryFlushReadRace) {
+  // configure cache
+  bufferlist inbl;
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier add\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name +
+    "\", \"force_nonempty\": \"--force-nonempty\" }",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier set-overlay\", \"pool\": \"" + pool_name +
+    "\", \"overlaypool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier cache-mode\", \"pool\": \"" + cache_pool_name +
+    "\", \"mode\": \"writeback\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle
+  cluster.wait_for_latest_osdmap();
+
+  // create/dirty object
+  {
+    bufferlist bl;
+    bl.append("hi there");
+    bufferptr bp(4000000);  // make it big!
+    bp.zero();
+    bl.append(bp);
+    ObjectWriteOperation op;
+    op.write_full(bl);
+    ASSERT_EQ(0, ioctx.operate("foo", &op));
+  }
+
+  // start a continuous stream of reads
+  read_ioctx = &ioctx;
+  test_lock.Lock();
+  for (int i = 0; i < max_reads; ++i) {
+    start_flush_read();
+    num_reads++;
+  }
+  test_lock.Unlock();
+
+  // try-flush
+  ObjectReadOperation op;
+  op.cache_try_flush();
+  librados::AioCompletion *completion = cluster.aio_create_completion();
+  ASSERT_EQ(0, cache_ioctx.aio_operate(
+      "foo", completion, &op,
+      librados::OPERATION_IGNORE_OVERLAY |
+      librados::OPERATION_SKIPRWLOCKS, NULL));
+
+  completion->wait_for_safe();
+  ASSERT_EQ(0, completion->get_return_value());
+  completion->release();
+
+  // stop reads
+  test_lock.Lock();
+  max_reads = 0;
+  while (num_reads > 0)
+    cond.Wait(test_lock);
+  test_lock.Unlock();
+
+  // tear down tiers
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove-overlay\", \"pool\": \"" + pool_name +
+    "\"}",
+    inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(
+    "{\"prefix\": \"osd tier remove\", \"pool\": \"" + pool_name +
+    "\", \"tierpool\": \"" + cache_pool_name + "\"}",
+    inbl, NULL, NULL));
+
+  // wait for maps to settle before next test
+  cluster.wait_for_latest_osdmap();
+}
+
+TEST_F(LibRadosTierECPP, HitSetNone) {
+  {
+    list< pair<time_t,time_t> > ls;
+    AioCompletion *c = librados::Rados::aio_create_completion();
+    ASSERT_EQ(0, ioctx.hit_set_list(123, c, &ls));
+    c->wait_for_complete();
+    ASSERT_EQ(0, c->get_return_value());
+    ASSERT_TRUE(ls.empty());
+    c->release();
+  }
+  {
+    bufferlist bl;
+    AioCompletion *c = librados::Rados::aio_create_completion();
+    ASSERT_EQ(0, ioctx.hit_set_get(123, c, 12345, &bl));
+    c->wait_for_complete();
+    ASSERT_EQ(-ENOENT, c->get_return_value());
+    c->release();
+  }
+}
+
+TEST_F(LibRadosTierECPP, HitSetRead) {
+  // enable hitset tracking for this pool
+  bufferlist inbl;
+  ASSERT_EQ(0, cluster.mon_command(set_pool_str(pool_name, "hit_set_count", 2),
+						inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(set_pool_str(pool_name, "hit_set_period", 600),
+						inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(set_pool_str(pool_name, "hit_set_type",
+						"explicit_object"),
+				   inbl, NULL, NULL));
+
+  // wait for maps to settle
+  cluster.wait_for_latest_osdmap();
+
+  ioctx.set_namespace("");
+
+  // keep reading until we see our object appear in the HitSet
+  utime_t start = ceph_clock_now(NULL);
+  utime_t hard_stop = start + utime_t(600, 0);
+
+  while (true) {
+    utime_t now = ceph_clock_now(NULL);
+    ASSERT_TRUE(now < hard_stop);
+
+    string name = "foo";
+    uint32_t hash = ioctx.get_object_hash_position(name);
+    hobject_t oid(sobject_t(name, CEPH_NOSNAP), "", hash,
+		  cluster.pool_lookup(pool_name.c_str()), "");
+
+    bufferlist bl;
+    ASSERT_EQ(-ENOENT, ioctx.read("foo", bl, 1, 0));
+
+    bufferlist hbl;
+    AioCompletion *c = librados::Rados::aio_create_completion();
+    ASSERT_EQ(0, ioctx.hit_set_get(hash, c, now.sec(), &hbl));
+    c->wait_for_complete();
+    c->release();
+
+    if (hbl.length()) {
+      bufferlist::iterator p = hbl.begin();
+      HitSet hs;
+      ::decode(hs, p);
+      if (hs.contains(oid)) {
+	cout << "ok, hit_set contains " << oid << std::endl;
+	break;
+      }
+      cout << "hmm, not in HitSet yet" << std::endl;
+    } else {
+      cout << "hmm, no HitSet yet" << std::endl;
+    }
+
+    sleep(1);
+  }
+}
+
+TEST_F(LibRadosTierECPP, HitSetWrite) {
+  int num_pg = _get_pg_num(cluster, pool_name);
+  assert(num_pg > 0);
+
+  // enable hitset tracking for this pool
+  bufferlist inbl;
+  ASSERT_EQ(0, cluster.mon_command(set_pool_str(pool_name, "hit_set_count", 8),
+						inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(set_pool_str(pool_name, "hit_set_period", 600),
+						inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(set_pool_str(pool_name, "hit_set_type",
+						"explicit_hash"),
+				   inbl, NULL, NULL));
+
+  // wait for maps to settle
+  cluster.wait_for_latest_osdmap();
+
+  ioctx.set_namespace("");
+
+  // do a bunch of writes
+  for (int i=0; i<1000; ++i) {
+    bufferlist bl;
+    bl.append("a");
+    ASSERT_EQ(1, ioctx.write(stringify(i), bl, 1, 0));
+  }
+
+  // get HitSets
+  std::map<int,HitSet> hitsets;
+  for (int i=0; i<num_pg; ++i) {
+    list< pair<time_t,time_t> > ls;
+    AioCompletion *c = librados::Rados::aio_create_completion();
+    ASSERT_EQ(0, ioctx.hit_set_list(i, c, &ls));
+    c->wait_for_complete();
+    c->release();
+    std::cout << "pg " << i << " ls " << ls << std::endl;
+    ASSERT_FALSE(ls.empty());
+
+    // get the latest
+    c = librados::Rados::aio_create_completion();
+    bufferlist bl;
+    ASSERT_EQ(0, ioctx.hit_set_get(i, c, ls.back().first, &bl));
+    c->wait_for_complete();
+    c->release();
+
+    //std::cout << "bl len is " << bl.length() << "\n";
+    //bl.hexdump(std::cout);
+    //std::cout << std::endl;
+
+    bufferlist::iterator p = bl.begin();
+    ::decode(hitsets[i], p);
+
+    // cope with racing splits by refreshing pg_num
+    if (i == num_pg - 1)
+      num_pg = _get_pg_num(cluster, pool_name);
+  }
+
+  for (int i=0; i<1000; ++i) {
+    string n = stringify(i);
+    uint32_t hash = ioctx.get_object_hash_position(n);
+    hobject_t oid(sobject_t(n, CEPH_NOSNAP), "", hash,
+		  cluster.pool_lookup(pool_name.c_str()), "");
+    std::cout << "checking for " << oid << std::endl;
+    bool found = false;
+    for (int p=0; p<num_pg; ++p) {
+      if (hitsets[p].contains(oid)) {
+	found = true;
+	break;
+      }
+    }
+    ASSERT_TRUE(found);
+  }
+}
+
+TEST_F(LibRadosTierECPP, HitSetTrim) {
+  unsigned count = 3;
+  unsigned period = 3;
+
+  // enable hitset tracking for this pool
+  bufferlist inbl;
+  ASSERT_EQ(0, cluster.mon_command(set_pool_str(pool_name, "hit_set_count", count),
+						inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(set_pool_str(pool_name, "hit_set_period", period),
+						inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(set_pool_str(pool_name, "hit_set_type", "bloom"),
+				   inbl, NULL, NULL));
+  ASSERT_EQ(0, cluster.mon_command(set_pool_str(pool_name, "hit_set_fpp", ".01"),
+				   inbl, NULL, NULL));
+
+  // wait for maps to settle
+  cluster.wait_for_latest_osdmap();
+
+  ioctx.set_namespace("");
+
+  // do a bunch of writes and make sure the hitsets rotate
+  utime_t start = ceph_clock_now(NULL);
+  utime_t hard_stop = start + utime_t(count * period * 12, 0);
+
+  time_t first = 0;
+  int bsize = alignment;
+  char *buf = (char *)new char[bsize];
+  memset(buf, 'f', bsize);
+
+  while (true) {
+    string name = "foo";
+    uint32_t hash = ioctx.get_object_hash_position(name);
+    hobject_t oid(sobject_t(name, CEPH_NOSNAP), "", hash, -1, "");
+
+    bufferlist bl;
+    bl.append(buf, bsize);
+    ASSERT_EQ(bsize, ioctx.append("foo", bl, bsize));
+
+    list<pair<time_t, time_t> > ls;
+    AioCompletion *c = librados::Rados::aio_create_completion();
+    ASSERT_EQ(0, ioctx.hit_set_list(hash, c, &ls));
+    c->wait_for_complete();
+    c->release();
+
+    ASSERT_TRUE(ls.size() <= count + 1);
+    cout << " got ls " << ls << std::endl;
+    if (!ls.empty()) {
+      if (!first) {
+	first = ls.front().first;
+	cout << "first is " << first << std::endl;
+      } else {
+	if (ls.front().first != first) {
+	  cout << "first now " << ls.front().first << ", trimmed" << std::endl;
+	  break;
+	}
+      }
+    }
+
+    utime_t now = ceph_clock_now(NULL);
+    ASSERT_TRUE(now < hard_stop);
+
+    sleep(1);
+  }
+  delete[] buf;
+}
 
 int main(int argc, char **argv)
 {