M(SendExternalTables, "Number of connections that are sending data for external tables to remote servers. External tables are used to implement GLOBAL IN and GLOBAL JOIN operators with distributed subqueries.") \
M(QueryThread, "Number of query processing threads") \
M(ReadonlyReplica, "Number of Replicated tables that are currently in readonly state due to re-initialization after ZooKeeper session loss or due to startup without ZooKeeper configured.") \
M(LeaderReplica, "Number of Replicated tables that are leaders. Leader replica is responsible for assigning merges, cleaning old blocks for deduplications and a few more bookkeeping tasks. There may be no more than one leader across all replicas at one moment of time. If there is no leader it will be elected soon or it indicate an issue.") \
M(MemoryTracking, "Total amount of memory (bytes) allocated by the server.") \
M(MemoryTrackingInBackgroundProcessingPool, "Total amount of memory (bytes) allocated in background processing pool (that is dedicated for backround merges, mutations and fetches). Note that this value may include a drift when the memory was allocated in a context of background processing pool and freed in other context or vice-versa. This happens naturally due to caches for tables indexes and doesn't indicate memory leaks.") \
M(MemoryTrackingInBackgroundMoveProcessingPool, "Total amount of memory (bytes) allocated in background processing pool (that is dedicated for backround moves). Note that this value may include a drift when the memory was allocated in a context of background processing pool and freed in other context or vice-versa. This happens naturally due to caches for tables indexes and doesn't indicate memory leaks.") \
...
...
@@ -39,7 +38,6 @@
M(MemoryTrackingInBackgroundBufferFlushSchedulePool, "Total amount of memory (bytes) allocated in background buffer flushes pool (that is dedicated for background buffer flushes).") \
M(MemoryTrackingInBackgroundDistributedSchedulePool, "Total amount of memory (bytes) allocated in background distributed schedule pool (that is dedicated for distributed sends).") \
M(MemoryTrackingForMerges, "Total amount of memory (bytes) allocated for background merges. Included in MemoryTrackingInBackgroundProcessingPool. Note that this value may include a drift when the memory was allocated in a context of background processing pool and freed in other context or vice-versa. This happens naturally due to caches for tables indexes and doesn't indicate memory leaks.") \
M(LeaderElection, "Number of Replicas participating in leader election. Equals to total number of replicas in usual cases.") \
M(EphemeralNode, "Number of ephemeral nodes hold in ZooKeeper.") \
M(ZooKeeperSession, "Number of sessions (connections) to ZooKeeper. Should be no more than one, because using more than one connection to ZooKeeper may lead to bugs due to lack of linearizability (stale reads) that ZooKeeper consistency model allows.") \
M(ZooKeeperWatch, "Number of watches (event subscriptions) in ZooKeeper.") \
M(SlowRead, "Number of reads from a file that were slow. This indicate system overload. Thresholds are controlled by read_backoff_* settings.") \
M(ReadBackoff, "Number of times the number of query processing threads was lowered due to slow reads.") \
\
M(ReplicaYieldLeadership, "Number of times Replicated table was yielded its leadership due to large replication lag relative to other replicas.") \
M(ReplicaPartialShutdown, "How many times Replicated table has to deinitialize its state due to session expiration in ZooKeeper. The state is reinitialized every time when ZooKeeper is available again.") \
\
M(SelectedParts, "Number of data parts selected to read from a MergeTree table.") \
...
...
@@ -131,7 +130,6 @@
M(MergeTreeDataWriterBlocksAlreadySorted, "Number of blocks INSERTed to MergeTree tables that appeared to be already sorted.") \
\
M(CannotRemoveEphemeralNode, "Number of times an error happened while trying to remove ephemeral node. This is not an issue, because our implementation of ZooKeeper library guarantee that the session will expire and the node will be removed.") \
M(LeaderElectionAcquiredLeadership, "Number of times a ReplicatedMergeTree table became a leader. Leader replica is responsible for assigning merges, cleaning old blocks for deduplications and a few more bookkeeping tasks.") \
\
M(RegexpCreated, "Compiled regular expressions. Identical regular expressions compiled just once and cached forever.") \
M(ContextLock, "Number of times the lock of Context was acquired or tried to acquire. This is global lock.") \
M(SettingUInt64, check_delay_period, 60, "Period to check replication delay and compare with other replicas.", 0) \
M(SettingUInt64, min_relative_delay_to_measure, 120, "Calculate relative replica delay only if absolute delay is not less that this value.", 0) \
M(SettingUInt64, cleanup_delay_period, 30, "Period to clean old queue logs, blocks hashes and parts.", 0) \
M(SettingUInt64, cleanup_delay_period_random_add, 10, "Add uniformly distributed value from 0 to x seconds to cleanup_delay_period to avoid thundering herd effect and subsequent DoS of ZooKeeper in case of very large number of tables.", 0) \
M(SettingUInt64, min_relative_delay_to_yield_leadership, 120, "Minimal delay from other replicas to yield leadership. Here and further 0 means unlimited.", 0) \
M(SettingUInt64, min_relative_delay_to_close, 300, "Minimal delay from other replicas to close, stop serving requests and not return Ok during status check.", 0) \
M(SettingUInt64, min_absolute_delay_to_close, 0, "Minimal absolute delay to close, stop serving requests and not return Ok during status check.", 0) \
@@ -95,7 +94,11 @@ struct MergeTreeSettings : public SettingsCollection<MergeTreeSettings>
M(SettingMaxThreads, max_part_loading_threads, 0, "The number of threads to load data parts at startup.", 0) \
M(SettingMaxThreads, max_part_removal_threads, 0, "The number of threads for concurrent removal of inactive data parts. One is usually enough, but in 'Google Compute Environment SSD Persistent Disks' file removal (unlink) operation is extraordinarily slow and you probably have to increase this number (recommended is up to 16).", 0) \
M(SettingUInt64, concurrent_part_removal_threshold, 100, "Activate concurrent part removal (see 'max_part_removal_threads') only if the number of inactive data parts is at least this.", 0) \
M(SettingString, storage_policy, "default", "Name of storage disk policy", 0)
M(SettingString, storage_policy, "default", "Name of storage disk policy", 0) \
\
/** Obsolete settings. Kept for backward compatibility only. */ \
M(SettingUInt64, min_relative_delay_to_yield_leadership, 120, "Obsolete setting, does nothing.", 0) \
M(SettingUInt64, check_delay_period, 60, "Obsolete setting, does nothing.", 0) \
LOG_INFO(log,"Relative replica delay ({} seconds) is bigger than threshold ({}). Will yield leadership.",relative_delay,storage_settings->min_relative_delay_to_yield_leadership);
