Pause pool rebalance when monitor detects that it can lead to any OSD becoming full

mon/etcd_schema.js

@@ -56,6 +56,7 @@ const etcd_tree = {
             osd_out_time: 600, // seconds. min: 0
             placement_levels: { datacenter: 1, rack: 2, host: 3, osd: 4, ... },
             use_old_pg_combinator: false,
+            osd_backfillfull_ratio: 0.99,
             // client and osd
             tcp_header_buffer_size: 65536,
             use_sync_send_recv: false,

mon/mon.js

@@ -74,6 +74,7 @@ class Mon
         this.state = JSON.parse(JSON.stringify(etcd_tree));
         this.prev_stats = { osd_stats: {}, osd_diff: {} };
         this.recheck_pgs_active = false;
+        this.updating_total_stats = false;
         this.watcher_active = false;
         this.old_pg_config = false;
         this.old_pg_stats_seen = false;
@@ -658,7 +659,13 @@ class Mon
                 this.etcd_watch_revision, pool_id, up_osds, osd_tree, real_prev_pgs, pool_res.pgs, pg_history);
         }
         new_pg_config.hash = tree_hash;
-        return await this.save_pg_config(new_pg_config, etcd_request);
+        const { backfillfull_pools } = sum_object_counts({ ...this.state, pg: { ...this.state.pg, config: new_pg_config } }, this.config);
+        new_pg_config.backfillfull_pools = backfillfull_pools.length ? backfillfull_pools : undefined;
+        if (!await this.save_pg_config(new_pg_config, etcd_request))
+        {
+            return false;
+        }
+        return true;
     }
 
     async save_pg_config(new_pg_config, etcd_request = { compare: [], success: [] })
@@ -730,7 +737,7 @@ class Mon
     async update_total_stats()
     {
         const txn = [];
-        const { object_counts, object_bytes } = sum_object_counts(this.state, this.config);
+        const { object_counts, object_bytes, backfillfull_pools } = sum_object_counts(this.state, this.config);
         let stats = sum_op_stats(this.state.osd, this.prev_stats);
         let { inode_stats, seen_pools } = sum_inode_stats(this.state, this.prev_stats);
         stats.object_counts = object_counts;
@@ -783,6 +790,16 @@ class Mon
         {
             await this.etcd.etcd_call('/kv/txn', { success: txn }, this.config.etcd_mon_timeout, 0);
         }
+        if (!this.recheck_pgs_active &&
+            backfillfull_pools.join(',') != ((this.state.pg.config||{}).no_rebalance_pools||[]).join(','))
+        {
+            console.log(
+                (backfillfull_pools.length ? 'Pool(s) '+backfillfull_pools.join(', ') : 'No pools')+
+                ' are backfillfull, applying rebalance configuration'
+            );
+            const new_pg_config = { ...this.state.pg.config, backfillfull_pools: backfillfull_pools.length ? backfillfull_pools : undefined };
+            await this.save_pg_config(new_pg_config);
+        }
     }
 
     schedule_update_stats()
@@ -794,7 +811,21 @@ class Mon
         this.stats_timer = setTimeout(() =>
         {
             this.stats_timer = null;
-            this.update_total_stats().catch(console.error);
+            if (this.updating_total_stats)
+            {
+                this.schedule_update_stats();
+                return;
+            }
+            this.updating_total_stats = true;
+            try
+            {
+                this.update_total_stats().catch(console.error);
+            }
+            catch (e)
+            {
+                console.error(e);
+            }
+            this.updating_total_stats = false;
         }, this.config.mon_stats_timeout);
     }
 

mon/stats.js

@@ -109,6 +109,8 @@ function sum_object_counts(state, global_config)
             pgstats[pool_id] = { ...(state.pg.stats[pool_id] || {}), ...(pgstats[pool_id] || {}) };
         }
     }
+    const pool_per_osd = {};
+    const clean_per_osd = {};
     for (const pool_id in pgstats)
     {
         let object_size = 0;
@@ -143,10 +145,38 @@ function sum_object_counts(state, global_config)
                         object_bytes[k] += BigInt(st[k+'_count']) * object_size;
                     }
                 }
+                if (st.object_count)
+                {
+                    for (const pg_osd in (((state.pg.config.items||{})[pool_id]||{})[pg_num]||{}).osd_set||[])
+                    {
+                        if (!(pg_osd in clean_per_osd))
+                        {
+                            clean_per_osd[pg_osd] = 0n;
+                        }
+                        clean_per_osd[pg_osd] += BigInt(st.object_count);
+                        pool_per_osd[pg_osd] = pool_per_osd[pg_osd]||{};
+                        pool_per_osd[pg_osd][pool_id] = true;
+                    }
+                }
             }
         }
     }
-    return { object_counts, object_bytes };
+    // If clean_per_osd[osd] is larger than osd capacity then it will fill up during rebalance
+    let backfillfull_pools = {};
+    for (const osd in clean_per_osd)
+    {
+        const st = state.osd.stats[osd];
+        if (st && st.size && st.data_block_size && (BigInt(st.size)/BigInt(st.data_block_size)*
+            BigInt((global_config.osd_backfillfull_ratio||0.99)*1000000)/1000000n) < clean_per_osd[osd])
+        {
+            for (const pool_id in pool_per_osd[osd])
+            {
+                backfillfull_pools[pool_id] = true;
+            }
+        }
+    }
+    backfillfull_pools = Object.keys(backfillfull_pools).sort();
+    return { object_counts, object_bytes, backfillfull_pools };
 }
 
 // sum_inode_stats(this.state, this.prev_stats)

src/client/etcd_state_client.cpp

@@ -785,7 +785,7 @@ void etcd_state_client_t::parse_state(const etcd_kv_t & kv)
         }
         for (auto & pool_item: value.object_items())
         {
-            pool_config_t pc;
+            pool_config_t pc = {};
             // ID
             pool_id_t pool_id;
             char null_byte = 0;
@@ -931,12 +931,28 @@ void etcd_state_client_t::parse_state(const etcd_kv_t & kv)
             // Ignore old key if the new one is present
             return;
         }
+        for (auto & pool_id_json: value["backfillfull_pools"].array_items())
+        {
+            auto pool_id = pool_id_json.uint64_value();
+            auto pool_it = this->pool_config.find(pool_id);
+            if (pool_it != this->pool_config.end())
+            {
+                pool_it->second.backfillfull |= 2;
+            }
+        }
         for (auto & pool_item: this->pool_config)
         {
             for (auto & pg_item: pool_item.second.pg_config)
             {
                 pg_item.second.config_exists = false;
             }
+            // 3 = was 1 and became 1, 0 = was 0 and became 0
+            if (pool_item.second.backfillfull == 2 || pool_item.second.backfillfull == 1)
+            {
+                if (on_change_backfillfull_hook)
+                    on_change_backfillfull_hook(pool_item.first);
+            }
+            pool_item.second.backfillfull = pool_item.second.backfillfull >> 1;
         }
         for (auto & pool_item: value["items"].object_items())
         {

src/client/etcd_state_client.h

@@ -62,6 +62,7 @@ struct pool_config_t
     std::map<pg_num_t, pg_config_t> pg_config;
     uint64_t scrub_interval;
     std::string used_for_fs;
+    int backfillfull;
 };
 
 struct inode_config_t
@@ -131,6 +132,7 @@ public:
     std::function<json11::Json()> load_pgs_checks_hook;
     std::function<void(bool)> on_load_pgs_hook;
     std::function<void()> on_change_pool_config_hook;
+    std::function<void(pool_id_t)> on_change_backfillfull_hook;
     std::function<void(pool_id_t, pg_num_t, osd_num_t)> on_change_pg_state_hook;
     std::function<void(pool_id_t, pg_num_t)> on_change_pg_history_hook;
     std::function<void(osd_num_t)> on_change_osd_state_hook;

src/osd/osd.h

@@ -226,6 +226,7 @@ class osd_t
     void parse_config(bool init);
     void init_cluster();
     void on_change_osd_state_hook(osd_num_t peer_osd);
+    void on_change_backfillfull_hook(pool_id_t pool_id);
     void on_change_pg_history_hook(pool_id_t pool_id, pg_num_t pg_num);
     void on_change_etcd_state_hook(std::map<std::string, etcd_kv_t> & changes);
     void on_load_config_hook(json11::Json::object & changes);

src/osd/osd_cluster.cpp

@@ -65,6 +65,7 @@ void osd_t::init_cluster()
         st_cli.tfd = tfd;
         st_cli.log_level = log_level;
         st_cli.on_change_osd_state_hook = [this](osd_num_t peer_osd) { on_change_osd_state_hook(peer_osd); };
+        st_cli.on_change_backfillfull_hook = [this](pool_id_t pool_id) { on_change_backfillfull_hook(pool_id); };
         st_cli.on_change_pg_history_hook = [this](pool_id_t pool_id, pg_num_t pg_num) { on_change_pg_history_hook(pool_id, pg_num); };
         st_cli.on_change_hook = [this](std::map<std::string, etcd_kv_t> & changes) { on_change_etcd_state_hook(changes); };
         st_cli.on_load_config_hook = [this](json11::Json::object & cfg) { on_load_config_hook(cfg); };
@@ -414,6 +415,14 @@ void osd_t::on_change_osd_state_hook(osd_num_t peer_osd)
     }
 }
 
+void osd_t::on_change_backfillfull_hook(pool_id_t pool_id)
+{
+    if (!(peering_state & (OSD_RECOVERING | OSD_FLUSHING_PGS)))
+    {
+        peering_state = peering_state | OSD_RECOVERING;
+    }
+}
+
 void osd_t::on_change_etcd_state_hook(std::map<std::string, etcd_kv_t> & changes)
 {
     if (changes.find(st_cli.etcd_prefix+"/config/global") != changes.end())

src/osd/osd_flush.cpp

@@ -252,10 +252,18 @@ bool osd_t::pick_next_recovery(osd_recovery_op_t &op)
             auto mask = recovery_last_degraded ? (PG_ACTIVE | PG_HAS_DEGRADED) : (PG_ACTIVE | PG_DEGRADED | PG_HAS_MISPLACED);
             auto check = recovery_last_degraded ? (PG_ACTIVE | PG_HAS_DEGRADED) : (PG_ACTIVE | PG_HAS_MISPLACED);
             // Restart scanning from the same PG as the last time
+        restart:
             for (auto pg_it = pgs.lower_bound(recovery_last_pg); pg_it != pgs.end(); pg_it++)
             {
                 if ((pg_it->second.state & mask) == check)
                 {
+                    auto pool_it = st_cli.pool_config.find(pg_it->first.pool_id);
+                    if (pool_it != st_cli.pool_config.end() && pool_it->second.backfillfull)
+                    {
+                        // Skip the pool
+                        recovery_last_pg.pool_id++;
+                        goto restart;
+                    }
                     auto & src = recovery_last_degraded ? pg_it->second.degraded_objects : pg_it->second.misplaced_objects;
                     assert(src.size() > 0);
                     // Restart scanning from the next object