uint32_t max_deviation,
int max,
const set<int64_t>& only_pools,
- OSDMap::Incremental *pending_inc)
+ OSDMap::Incremental *pending_inc,
+ std::random_device::result_type *p_seed)
{
ldout(cct, 10) << __func__ << " pools " << only_pools << dendl;
- OSDMap tmp;
+ OSDMap tmp_osd_map;
// Can't be less than 1 pg
if (max_deviation < 1)
max_deviation = 1;
- tmp.deepish_copy_from(*this);
+ tmp_osd_map.deepish_copy_from(*this);
int num_changed = 0;
map<int,set<pg_t>> pgs_by_osd;
int total_pgs = 0;
float osd_weight_total = 0;
map<int,float> osd_weight;
- for (auto& i : pools) {
- if (!only_pools.empty() && !only_pools.count(i.first))
- continue;
- for (unsigned ps = 0; ps < i.second.get_pg_num(); ++ps) {
- pg_t pg(ps, i.first);
- vector<int> up;
- tmp.pg_to_up_acting_osds(pg, &up, nullptr, nullptr, nullptr);
- ldout(cct, 20) << __func__ << " " << pg << " up " << up << dendl;
- for (auto osd : up) {
- if (osd != CRUSH_ITEM_NONE)
- pgs_by_osd[osd].insert(pg);
- }
- }
- total_pgs += i.second.get_size() * i.second.get_pg_num();
- map<int,float> pmap;
- int ruleno = i.second.get_crush_rule();
- tmp.crush->get_rule_weight_osd_map(ruleno, &pmap);
- ldout(cct,20) << __func__ << " pool " << i.first
- << " ruleno " << ruleno
- << " weight-map " << pmap
- << dendl;
- for (auto p : pmap) {
- auto adjusted_weight = tmp.get_weightf(p.first) * p.second;
- if (adjusted_weight == 0) {
- continue;
- }
- osd_weight[p.first] += adjusted_weight;
- osd_weight_total += adjusted_weight;
- }
- }
- for (auto& i : osd_weight) {
- int pgs = 0;
- auto p = pgs_by_osd.find(i.first);
- if (p != pgs_by_osd.end())
- pgs = p->second.size();
- else
- pgs_by_osd.emplace(i.first, set<pg_t>());
- ldout(cct, 20) << " osd." << i.first << " weight " << i.second
- << " pgs " << pgs << dendl;
+ if (max <= 0) {
+ lderr(cct) << __func__ << " abort due to max <= 0" << dendl;
+ return 0;
}
+
+ osd_weight_total = build_pool_pgs_info(cct, only_pools, tmp_osd_map,
+ total_pgs, pgs_by_osd, osd_weight);
if (osd_weight_total == 0) {
lderr(cct) << __func__ << " abort due to osd_weight_total == 0" << dendl;
return 0;
}
+
float pgs_per_weight = total_pgs / osd_weight_total;
ldout(cct, 10) << " osd_weight_total " << osd_weight_total << dendl;
ldout(cct, 10) << " pgs_per_weight " << pgs_per_weight << dendl;
- if (max <= 0) {
- lderr(cct) << __func__ << " abort due to max <= 0" << dendl;
- return 0;
- }
float stddev = 0;
map<int,float> osd_deviation; // osd, deviation(pgs)
multimap<float,int> deviation_osd; // deviation(pgs), osd
- float cur_max_deviation = 0;
- for (auto& i : pgs_by_osd) {
- // make sure osd is still there (belongs to this crush-tree)
- ceph_assert(osd_weight.count(i.first));
- float target = osd_weight[i.first] * pgs_per_weight;
- float deviation = (float)i.second.size() - target;
- ldout(cct, 20) << " osd." << i.first
- << "\tpgs " << i.second.size()
- << "\ttarget " << target
- << "\tdeviation " << deviation
- << dendl;
- osd_deviation[i.first] = deviation;
- deviation_osd.insert(make_pair(deviation, i.first));
- stddev += deviation * deviation;
- if (fabsf(deviation) > cur_max_deviation)
- cur_max_deviation = fabsf(deviation);
- }
+ float cur_max_deviation = calc_deviations(cct, pgs_by_osd, osd_weight, pgs_per_weight,
+ osd_deviation, deviation_osd, stddev);
+
ldout(cct, 20) << " stdev " << stddev << " max_deviation " << cur_max_deviation << dendl;
if (cur_max_deviation <= max_deviation) {
ldout(cct, 10) << __func__ << " distribution is almost perfect"
<< dendl;
return 0;
}
+
bool skip_overfull = false;
auto aggressive =
cct->_conf.get_val<bool>("osd_calc_pg_upmaps_aggressively");
auto local_fallback_retries =
cct->_conf.get_val<uint64_t>("osd_calc_pg_upmaps_local_fallback_retries");
+
while (max--) {
ldout(cct, 30) << "Top of loop #" << max+1 << dendl;
// build overfull and underfull
bool using_more_overfull = false;
vector<int> underfull;
vector<int> more_underfull;
- for (auto i = deviation_osd.rbegin(); i != deviation_osd.rend(); i++) {
- ldout(cct, 30) << " check " << i->first << " <= " << max_deviation << dendl;
- if (i->first <= 0)
- break;
- if (i->first > max_deviation) {
- ldout(cct, 30) << " add overfull osd." << i->second << dendl;
- overfull.insert(i->second);
- } else {
- more_overfull.insert(i->second);
- }
- }
+ fill_overfull_underfull(cct, deviation_osd, max_deviation,
+ overfull, more_overfull,
+ underfull, more_underfull);
- for (auto i = deviation_osd.begin(); i != deviation_osd.end(); i++) {
- ldout(cct, 30) << " check " << i->first << " >= " << -(int)max_deviation << dendl;
- if (i->first >= 0)
- break;
- if (i->first < -(int)max_deviation) {
- ldout(cct, 30) << " add underfull osd." << i->second << dendl;
- underfull.push_back(i->second);
- } else {
- more_underfull.push_back(i->second);
- }
- }
if (underfull.empty() && overfull.empty()) {
ldout(cct, 20) << __func__ << " failed to build overfull and underfull" << dendl;
break;
}
if (aggressive) {
// shuffle PG list so they all get equal (in)attention
- std::random_device rd;
- std::default_random_engine rng{rd()};
- std::shuffle(pgs.begin(), pgs.end(), rng);
+ std::shuffle(pgs.begin(), pgs.end(), get_random_engine(cct, p_seed));
}
// look for remaps we can un-remap
- for (auto pg : pgs) {
- auto p = tmp.pg_upmap_items.find(pg);
- if (p == tmp.pg_upmap_items.end())
- continue;
- mempool::osdmap::vector<pair<int32_t,int32_t>> new_upmap_items;
- for (auto q : p->second) {
- if (q.second == osd) {
- ldout(cct, 10) << " will try dropping existing"
- << " remapping pair "
- << q.first << " -> " << q.second
- << " which remapped " << pg
- << " into overfull osd." << osd
- << dendl;
- temp_pgs_by_osd[q.second].erase(pg);
- temp_pgs_by_osd[q.first].insert(pg);
- } else {
- new_upmap_items.push_back(q);
- }
- }
- if (new_upmap_items.empty()) {
- // drop whole item
- ldout(cct, 10) << " existing pg_upmap_items " << p->second
- << " remapped " << pg << " into overfull osd." << osd
- << ", will try cancelling it entirely"
- << dendl;
- to_unmap.insert(pg);
- goto test_change;
- } else if (new_upmap_items.size() != p->second.size()) {
- // drop single remapping pair, updating
- ceph_assert(new_upmap_items.size() < p->second.size());
- ldout(cct, 10) << " existing pg_upmap_items " << p->second
- << " remapped " << pg << " into overfull osd." << osd
- << ", new_pg_upmap_items now " << new_upmap_items
- << dendl;
- to_upmap[pg] = new_upmap_items;
- goto test_change;
- }
- }
+ if (try_drop_remap_overfull(cct, pgs, tmp_osd_map, osd,
+ temp_pgs_by_osd, to_unmap, to_upmap))
+ goto test_change;
// try upmap
for (auto pg : pgs) {
- auto temp_it = tmp.pg_upmap.find(pg);
- if (temp_it != tmp.pg_upmap.end()) {
+ auto temp_it = tmp_osd_map.pg_upmap.find(pg);
+ if (temp_it != tmp_osd_map.pg_upmap.end()) {
// leave pg_upmap alone
// it must be specified by admin since balancer does not
// support pg_upmap yet
<< dendl;
continue;
}
- auto pg_pool_size = tmp.get_pg_pool_size(pg);
+ auto pg_pool_size = tmp_osd_map.get_pg_pool_size(pg);
mempool::osdmap::vector<pair<int32_t,int32_t>> new_upmap_items;
set<int> existing;
- auto it = tmp.pg_upmap_items.find(pg);
- if (it != tmp.pg_upmap_items.end() &&
- it->second.size() >= (size_t)pg_pool_size) {
- ldout(cct, 10) << " " << pg << " already has full-size pg_upmap_items "
- << it->second << ", skipping"
- << dendl;
- continue;
- } else if (it != tmp.pg_upmap_items.end()) {
- ldout(cct, 10) << " " << pg << " already has pg_upmap_items "
- << it->second
- << dendl;
- new_upmap_items = it->second;
- // build existing too (for dedup)
- for (auto i : it->second) {
- existing.insert(i.first);
- existing.insert(i.second);
- }
+ auto it = tmp_osd_map.pg_upmap_items.find(pg);
+ if (it != tmp_osd_map.pg_upmap_items.end()) {
+ auto& um_items = it->second;
+ if (um_items.size() >= (size_t)pg_pool_size) {
+ ldout(cct, 10) << " " << pg << " already has full-size pg_upmap_items "
+ << um_items << ", skipping"
+ << dendl;
+ continue;
+ } else {
+ ldout(cct, 10) << " " << pg << " already has pg_upmap_items "
+ << um_items
+ << dendl;
+ new_upmap_items = um_items;
+ // build existing too (for dedup)
+ for (auto [um_from, um_to] : um_items) {
+ existing.insert(um_from);
+ existing.insert(um_to);
+ }
+ }
// fall through
// to see if we can append more remapping pairs
- }
+ }
ldout(cct, 10) << " trying " << pg << dendl;
vector<int> raw, orig, out;
- tmp.pg_to_raw_upmap(pg, &raw, &orig); // including existing upmaps too
+ tmp_osd_map.pg_to_raw_upmap(pg, &raw, &orig); // including existing upmaps too
if (!try_pg_upmap(cct, pg, overfull, underfull, more_underfull, &orig, &out)) {
continue;
}
continue;
}
ceph_assert(orig != out);
- int pos = -1;
- float max_dev = 0;
- for (unsigned i = 0; i < out.size(); ++i) {
- if (orig[i] == out[i])
- continue; // skip invalid remappings
- if (existing.count(orig[i]) || existing.count(out[i]))
- continue; // we want new remappings only!
- if (osd_deviation[orig[i]] > max_dev) {
- max_dev = osd_deviation[orig[i]];
- pos = i;
- ldout(cct, 30) << "Max osd." << orig[i] << " pos " << i << " dev " << osd_deviation[orig[i]] << dendl;
- }
- }
+ int pos = find_best_remap(cct, orig, out, existing, osd_deviation);
if (pos != -1) {
- int i = pos;
- ldout(cct, 10) << " will try adding new remapping pair "
- << orig[i] << " -> " << out[i] << " for " << pg
- << (orig[i] != osd ? " NOT selected osd" : "")
- << dendl;
- existing.insert(orig[i]);
- existing.insert(out[i]);
- temp_pgs_by_osd[orig[i]].erase(pg);
- temp_pgs_by_osd[out[i]].insert(pg);
- ceph_assert(new_upmap_items.size() < (size_t)pg_pool_size);
- new_upmap_items.push_back(make_pair(orig[i], out[i]));
// append new remapping pairs slowly
// This way we can make sure that each tiny change will
// definitely make distribution of PGs converging to
// the perfect status.
- to_upmap[pg] = new_upmap_items;
+ add_remap_pair(cct, orig[pos], out[pos], pg, (size_t)pg_pool_size,
+ osd, existing, temp_pgs_by_osd,
+ new_upmap_items, to_upmap);
goto test_change;
}
}
ceph_assert(!(to_unmap.size() || to_upmap.size()));
ldout(cct, 10) << " failed to find any changes for overfull osds"
<< dendl;
- for (auto& p : deviation_osd) {
- if (std::find(underfull.begin(), underfull.end(), p.second) ==
+ for (auto& [deviation, osd] : deviation_osd) {
+ if (std::find(underfull.begin(), underfull.end(), osd) ==
underfull.end())
break;
- int osd = p.second;
- float deviation = p.first;
float target = osd_weight[osd] * pgs_per_weight;
ceph_assert(target > 0);
if (fabsf(deviation) < max_deviation) {
break;
}
// look for remaps we can un-remap
- vector<pair<pg_t,
- mempool::osdmap::vector<pair<int32_t,int32_t>>>> candidates;
- candidates.reserve(tmp.pg_upmap_items.size());
- for (auto& i : tmp.pg_upmap_items) {
- if (to_skip.count(i.first))
- continue;
- if (!only_pools.empty() && !only_pools.count(i.first.pool()))
- continue;
- candidates.push_back(make_pair(i.first, i.second));
- }
- if (aggressive) {
- // shuffle candidates so they all get equal (in)attention
- std::random_device rd;
- std::default_random_engine rng{rd()};
- std::shuffle(candidates.begin(), candidates.end(), rng);
- }
- for (auto& i : candidates) {
- auto pg = i.first;
- mempool::osdmap::vector<pair<int32_t,int32_t>> new_upmap_items;
- for (auto& j : i.second) {
- if (j.first == osd) {
- ldout(cct, 10) << " will try dropping existing"
- << " remapping pair "
- << j.first << " -> " << j.second
- << " which remapped " << pg
- << " out from underfull osd." << osd
- << dendl;
- temp_pgs_by_osd[j.second].erase(pg);
- temp_pgs_by_osd[j.first].insert(pg);
- } else {
- new_upmap_items.push_back(j);
- }
- }
- if (new_upmap_items.empty()) {
- // drop whole item
- ldout(cct, 10) << " existing pg_upmap_items " << i.second
- << " remapped " << pg
- << " out from underfull osd." << osd
- << ", will try cancelling it entirely"
- << dendl;
- to_unmap.insert(pg);
- goto test_change;
- } else if (new_upmap_items.size() != i.second.size()) {
- // drop single remapping pair, updating
- ceph_assert(new_upmap_items.size() < i.second.size());
- ldout(cct, 10) << " existing pg_upmap_items " << i.second
- << " remapped " << pg
- << " out from underfull osd." << osd
- << ", new_pg_upmap_items now " << new_upmap_items
- << dendl;
- to_upmap[pg] = new_upmap_items;
- goto test_change;
- }
+ candidates_t candidates = build_candidates(cct, tmp_osd_map, to_skip,
+ only_pools, aggressive, p_seed);
+ if (try_drop_remap_underfull(cct, candidates, osd, temp_pgs_by_osd,
+ to_unmap, to_upmap)) {
+ goto test_change;
}
}
float new_stddev = 0;
map<int,float> temp_osd_deviation;
multimap<float,int> temp_deviation_osd;
- float cur_max_deviation = 0;
- for (auto& i : temp_pgs_by_osd) {
- // make sure osd is still there (belongs to this crush-tree)
- ceph_assert(osd_weight.count(i.first));
- float target = osd_weight[i.first] * pgs_per_weight;
- float deviation = (float)i.second.size() - target;
- ldout(cct, 20) << " osd." << i.first
- << "\tpgs " << i.second.size()
- << "\ttarget " << target
- << "\tdeviation " << deviation
- << dendl;
- temp_osd_deviation[i.first] = deviation;
- temp_deviation_osd.insert(make_pair(deviation, i.first));
- new_stddev += deviation * deviation;
- if (fabsf(deviation) > cur_max_deviation)
- cur_max_deviation = fabsf(deviation);
- }
+ float cur_max_deviation = calc_deviations(cct, temp_pgs_by_osd, osd_weight,
+ pgs_per_weight, temp_osd_deviation,
+ temp_deviation_osd, new_stddev);
ldout(cct, 10) << " stddev " << stddev << " -> " << new_stddev << dendl;
if (new_stddev >= stddev) {
if (!aggressive) {
pgs_by_osd = temp_pgs_by_osd;
osd_deviation = temp_osd_deviation;
deviation_osd = temp_deviation_osd;
- for (auto& i : to_unmap) {
- ldout(cct, 10) << " unmap pg " << i << dendl;
- ceph_assert(tmp.pg_upmap_items.count(i));
- tmp.pg_upmap_items.erase(i);
- pending_inc->old_pg_upmap_items.insert(i);
- ++num_changed;
- }
- for (auto& i : to_upmap) {
- ldout(cct, 10) << " upmap pg " << i.first
- << " new pg_upmap_items " << i.second
- << dendl;
- tmp.pg_upmap_items[i.first] = i.second;
- pending_inc->new_pg_upmap_items[i.first] = i.second;
- ++num_changed;
- }
+
+ num_changed += pack_upmap_results(cct, to_unmap, to_upmap, tmp_osd_map, pending_inc);
+
ldout(cct, 20) << " stdev " << stddev << " max_deviation " << cur_max_deviation << dendl;
if (cur_max_deviation <= max_deviation) {
ldout(cct, 10) << __func__ << " Optimization plan is almost perfect"
return num_changed;
}
+float OSDMap::build_pool_pgs_info (
+ CephContext *cct,
+ const std::set<int64_t>& only_pools, ///< [optional] restrict to pool
+ const OSDMap& tmp_osd_map,
+ int& total_pgs,
+ map<int,set<pg_t>>& pgs_by_osd,
+ map<int,float>& osd_weight)
+{
+ //
+ // This function builds some data structures that are used by calc_pg_upmaps.
+ // Specifically it builds pgs_by_osd and osd_weight maps, updates total_pgs
+ // and returns the osd_weight_total
+ //
+ float osd_weight_total = 0.0;
+ for (auto& [pid, pdata] : pools) {
+ if (!only_pools.empty() && !only_pools.count(pid))
+ continue;
+ for (unsigned ps = 0; ps < pdata.get_pg_num(); ++ps) {
+ pg_t pg(ps, pid);
+ vector<int> up;
+ tmp_osd_map.pg_to_up_acting_osds(pg, &up, nullptr, nullptr, nullptr);
+ ldout(cct, 20) << __func__ << " " << pg << " up " << up << dendl;
+ for (auto osd : up) {
+ if (osd != CRUSH_ITEM_NONE)
+ pgs_by_osd[osd].insert(pg);
+ }
+ }
+ total_pgs += pdata.get_size() * pdata.get_pg_num();
+
+ map<int,float> pmap;
+ int ruleno = pdata.get_crush_rule();
+ tmp_osd_map.crush->get_rule_weight_osd_map(ruleno, &pmap);
+ ldout(cct,20) << __func__ << " pool " << pid
+ << " ruleno " << ruleno
+ << " weight-map " << pmap
+ << dendl;
+ for (auto [oid, oweight] : pmap) {
+ auto adjusted_weight = tmp_osd_map.get_weightf(oid) * oweight;
+ if (adjusted_weight == 0) {
+ continue;
+ }
+ osd_weight[oid] += adjusted_weight;
+ osd_weight_total += adjusted_weight;
+ }
+ }
+ for (auto& [oid, oweight] : osd_weight) {
+ int pgs = 0;
+ auto p = pgs_by_osd.find(oid);
+ if (p != pgs_by_osd.end())
+ pgs = p->second.size();
+ else
+ pgs_by_osd.emplace(oid, set<pg_t>());
+ ldout(cct, 20) << " osd." << oid << " weight " << oweight
+ << " pgs " << pgs << dendl;
+ }
+ return osd_weight_total;
+
+} // return total weight of all OSDs
+
+float OSDMap::calc_deviations (
+ CephContext *cct,
+ const map<int,set<pg_t>>& pgs_by_osd,
+ const map<int,float>& osd_weight,
+ float pgs_per_weight,
+ map<int,float>& osd_deviation,
+ multimap<float,int>& deviation_osd,
+ float& stddev) // return current max deviation
+{
+ //
+ // This function calculates the 2 maps osd_deviation and deviation_osd which
+ // hold the deviation between the current number of PGs which map to an OSD
+ // and the optimal number. Ot also calculates the stddev of the deviations and
+ // returns the current max deviation.
+ // NOTE - the calculation is not exactly stddev it is actually sttdev^2 but as
+ // long as it is monotonic with stddev (and it is), it is sufficient for
+ // the balancer code.
+ //
+ float cur_max_deviation = 0.0;
+ stddev = 0.0;
+ for (auto& [oid, opgs] : pgs_by_osd) {
+ // make sure osd is still there (belongs to this crush-tree)
+ ceph_assert(osd_weight.count(oid));
+ float target = osd_weight.at(oid) * pgs_per_weight;
+ float deviation = (float)opgs.size() - target;
+ ldout(cct, 20) << " osd." << oid
+ << "\tpgs " << opgs.size()
+ << "\ttarget " << target
+ << "\tdeviation " << deviation
+ << dendl;
+ osd_deviation[oid] = deviation;
+ deviation_osd.insert(make_pair(deviation, oid));
+ stddev += deviation * deviation;
+ if (fabsf(deviation) > cur_max_deviation)
+ cur_max_deviation = fabsf(deviation);
+ }
+ return cur_max_deviation;
+}
+
+void OSDMap::fill_overfull_underfull (
+ CephContext *cct,
+ const std::multimap<float,int>& deviation_osd,
+ int max_deviation,
+ std::set<int>& overfull,
+ std::set<int>& more_overfull,
+ std::vector<int>& underfull,
+ std::vector<int>& more_underfull)
+{
+ //
+ // This function just fills the overfull and underfull data structures for the
+ // use of calc_pg_upmaps
+ //
+ for (auto i = deviation_osd.rbegin(); i != deviation_osd.rend(); i++) {
+ auto& odev = i->first;
+ auto& oid = i->second;
+ ldout(cct, 30) << " check " << odev << " <= " << max_deviation << dendl;
+ if (odev <= 0)
+ break;
+ if (odev > max_deviation) {
+ ldout(cct, 30) << " add overfull osd." << oid << dendl;
+ overfull.insert(oid);
+ } else {
+ more_overfull.insert(oid);
+ }
+ }
+
+ for (auto i = deviation_osd.begin(); i != deviation_osd.end(); i++) {
+ auto& odev = i->first;
+ auto& oid = i->second;
+ ldout(cct, 30) << " check " << odev << " >= " << -(int)max_deviation << dendl;
+ if (odev >= 0)
+ break;
+ if (odev < -(int)max_deviation) {
+ ldout(cct, 30) << " add underfull osd." << oid << dendl;
+ underfull.push_back(oid);
+ } else {
+ more_underfull.push_back(oid);
+ }
+ }
+}
+
+int OSDMap::pack_upmap_results(
+ CephContext *cct,
+ const std::set<pg_t>& to_unmap,
+ const std::map<pg_t, mempool::osdmap::vector<std::pair<int, int>>>& to_upmap,
+ OSDMap& tmp_osd_map,
+ OSDMap::Incremental *pending_inc)
+{
+ //
+ // This function takes the input from the local variables to_unmap and to_upmap
+ // and updates tmp_osd_map (so that another iteration can run) and pending_inc
+ // (so that the results are visible outside calc_pg_upmaps)
+ //
+ int num_changed = 0;
+ for (auto& i : to_unmap) {
+ ldout(cct, 10) << " unmap pg " << i << dendl;
+ ceph_assert(tmp_osd_map.pg_upmap_items.count(i));
+ tmp_osd_map.pg_upmap_items.erase(i);
+ pending_inc->old_pg_upmap_items.insert(i);
+ ++num_changed;
+ }
+ for (auto& [pg, um_items] : to_upmap) {
+ ldout(cct, 10) << " upmap pg " << pg
+ << " new pg_upmap_items " << um_items
+ << dendl;
+ tmp_osd_map.pg_upmap_items[pg] = um_items;
+ pending_inc->new_pg_upmap_items[pg] = um_items;
+ ++num_changed;
+ }
+
+ return num_changed;
+}
+
+std::default_random_engine OSDMap::get_random_engine(
+ CephContext *cct,
+ std::random_device::result_type *p_seed)
+{
+ //
+ // This function creates a random_engine to be used for shuffling.
+ // When p_seed == nullptr it generates random engine with a seed from /dev/random
+ // when p_seed is not null, it uses (*p_seed + seed_set) as the seed and
+ // increments seed_set. This is used in order to craete regression test without
+ // random effect on the results.
+ //
+ static std::random_device::result_type seed_set = 0;
+ std::random_device::result_type seed;
+ if (p_seed == nullptr) {
+ std::random_device rd;
+ seed = rd();
+ }
+ else {
+ seed = *p_seed + seed_set;
+ ldout(cct, 30) << " Starting random engine with seed "
+ << seed << dendl;
+ seed_set++;
+ }
+ return std::default_random_engine{seed};
+}
+
+bool OSDMap::try_drop_remap_overfull(
+ CephContext *cct,
+ const std::vector<pg_t>& pgs,
+ const OSDMap& tmp_osd_map,
+ int osd,
+ map<int,std::set<pg_t>>& temp_pgs_by_osd,
+ set<pg_t>& to_unmap,
+ map<pg_t, mempool::osdmap::vector<pair<int32_t,int32_t>>>& to_upmap)
+{
+ //
+ // This function tries to drop existimg upmap items which map data to overfull
+ // OSDs. It updates temp_pgs_by_osd, to_unmap and to_upmap and rerturns true
+ // if it found an item that can be dropped, false if not.
+ //
+ for (auto pg : pgs) {
+ auto p = tmp_osd_map.pg_upmap_items.find(pg);
+ if (p == tmp_osd_map.pg_upmap_items.end())
+ continue;
+ mempool::osdmap::vector<pair<int32_t,int32_t>> new_upmap_items;
+ auto& pg_upmap_items = p->second;
+ for (auto um_pair : pg_upmap_items) {
+ auto& um_from = um_pair.first;
+ auto& um_to = um_pair.second;
+ if (um_to == osd) {
+ ldout(cct, 10) << " will try dropping existing"
+ << " remapping pair "
+ << um_from << " -> " << um_to
+ << " which remapped " << pg
+ << " into overfull osd." << osd
+ << dendl;
+ temp_pgs_by_osd[um_to].erase(pg);
+ temp_pgs_by_osd[um_from].insert(pg);
+ } else {
+ new_upmap_items.push_back(um_pair);
+ }
+ }
+ if (new_upmap_items.empty()) {
+ // drop whole item
+ ldout(cct, 10) << " existing pg_upmap_items " << pg_upmap_items
+ << " remapped " << pg << " into overfull osd." << osd
+ << ", will try cancelling it entirely"
+ << dendl;
+ to_unmap.insert(pg);
+ return true;
+ } else if (new_upmap_items.size() != pg_upmap_items.size()) {
+ // drop single remapping pair, updating
+ ceph_assert(new_upmap_items.size() < pg_upmap_items.size());
+ ldout(cct, 10) << " existing pg_upmap_items " << pg_upmap_items
+ << " remapped " << pg << " into overfull osd." << osd
+ << ", new_pg_upmap_items now " << new_upmap_items
+ << dendl;
+ to_upmap[pg] = new_upmap_items;
+ return true;
+ }
+ }
+ return false;
+}
+
+bool OSDMap::try_drop_remap_underfull(
+ CephContext *cct,
+ const candidates_t& candidates,
+ int osd,
+ map<int,std::set<pg_t>>& temp_pgs_by_osd,
+ set<pg_t>& to_unmap,
+ map<pg_t, mempool::osdmap::vector<std::pair<int32_t,int32_t>>>& to_upmap)
+{
+ //
+ // This function tries to drop existimg upmap items which map data from underfull
+ // OSDs. It updates temp_pgs_by_osd, to_unmap and to_upmap and rerturns true
+ // if it found an item that can be dropped, false if not.
+ //
+ for (auto& [pg, um_pairs] : candidates) {
+ mempool::osdmap::vector<pair<int32_t,int32_t>> new_upmap_items;
+ for (auto& ump : um_pairs) {
+ auto& um_from = ump.first;
+ auto& um_to = ump.second;
+ if (um_from == osd) {
+ ldout(cct, 10) << " will try dropping existing"
+ << " remapping pair "
+ << um_from << " -> " << um_to
+ << " which remapped " << pg
+ << " out from underfull osd." << osd
+ << dendl;
+ temp_pgs_by_osd[um_to].erase(pg);
+ temp_pgs_by_osd[um_from].insert(pg);
+ } else {
+ new_upmap_items.push_back(ump);
+ }
+ }
+ if (new_upmap_items.empty()) {
+ // drop whole item
+ ldout(cct, 10) << " existing pg_upmap_items " << um_pairs
+ << " remapped " << pg
+ << " out from underfull osd." << osd
+ << ", will try cancelling it entirely"
+ << dendl;
+ to_unmap.insert(pg);
+ return true;
+ } else if (new_upmap_items.size() != um_pairs.size()) {
+ // drop single remapping pair, updating
+ ceph_assert(new_upmap_items.size() < um_pairs.size());
+ ldout(cct, 10) << " existing pg_upmap_items " << um_pairs
+ << " remapped " << pg
+ << " out from underfull osd." << osd
+ << ", new_pg_upmap_items now " << new_upmap_items
+ << dendl;
+ to_upmap[pg] = new_upmap_items;
+ return true;
+ }
+ }
+ return false;
+}
+
+void OSDMap::add_remap_pair(
+ CephContext *cct,
+ int orig,
+ int out,
+ pg_t pg,
+ size_t pg_pool_size,
+ int osd,
+ set<int>& existing,
+ map<int,set<pg_t>>& temp_pgs_by_osd,
+ mempool::osdmap::vector<pair<int32_t,int32_t>> new_upmap_items,
+ map<pg_t, mempool::osdmap::vector<pair<int32_t,int32_t>>>& to_upmap)
+{
+ //
+ // add a single remap pair (in pg <pg> remap osd from <orig> to <out>) to all
+ // the relevant data structures
+ //
+ ldout(cct, 10) << " will try adding new remapping pair "
+ << orig << " -> " << out << " for " << pg
+ << (orig != osd ? " NOT selected osd" : "")
+ << dendl;
+ existing.insert(orig);
+ existing.insert(out);
+ temp_pgs_by_osd[orig].erase(pg);
+ temp_pgs_by_osd[out].insert(pg);
+ ceph_assert(new_upmap_items.size() < pg_pool_size);
+ new_upmap_items.push_back(make_pair(orig, out));
+ // append new remapping pairs slowly
+ // This way we can make sure that each tiny change will
+ // definitely make distribution of PGs converging to
+ // the perfect status.
+ to_upmap[pg] = new_upmap_items;
+
+}
+
+int OSDMap::find_best_remap (
+ CephContext *cct,
+ const vector<int>& orig,
+ const vector<int>& out,
+ const set<int>& existing,
+ const map<int,float> osd_deviation)
+{
+ //
+ // Find the best remap from the suggestions in orig and out - the best remap
+ // is the one which maps from the OSD with the largest deviatoion (from the
+ // OSDs which are part of orig)
+ //
+ int best_pos = -1;
+ float max_dev = 0;
+ for (unsigned i = 0; i < out.size(); ++i) {
+ if (orig[i] == out[i])
+ continue; // skip invalid remappings
+ if (existing.count(orig[i]) || existing.count(out[i]))
+ continue; // we want new remappings only!
+ if (osd_deviation.at(orig[i]) > max_dev) {
+ max_dev = osd_deviation.at(orig[i]);
+ best_pos = i;
+ ldout(cct, 30) << "Max osd." << orig[i] << " pos " << i << " dev " << osd_deviation.at(orig[i]) << dendl;
+ }
+ }
+ return best_pos;
+}
+
+OSDMap::candidates_t OSDMap::build_candidates(
+ CephContext *cct,
+ const OSDMap& tmp_osd_map,
+ const set<pg_t> to_skip,
+ const set<int64_t>& only_pools,
+ bool aggressive,
+ std::random_device::result_type *p_seed)
+{
+ //
+ // build the candidates data structure
+ //
+ candidates_t candidates;
+ candidates.reserve(tmp_osd_map.pg_upmap_items.size());
+ for (auto& [pg, um_pair] : tmp_osd_map.pg_upmap_items) {
+ if (to_skip.count(pg))
+ continue;
+ if (!only_pools.empty() && !only_pools.count(pg.pool()))
+ continue;
+ candidates.push_back(make_pair(pg, um_pair));
+ }
+ if (aggressive) {
+ // shuffle candidates so they all get equal (in)attention
+ std::shuffle(candidates.begin(), candidates.end(), get_random_engine(cct, p_seed));
+ }
+ return candidates;
+}
+
int OSDMap::get_osds_by_bucket_name(const string &name, set<int> *osds) const
{
return crush->get_leaves(name, osds);
projects / ceph.git / commitdiff