diff --git a/identify-slow-queries.md b/identify-slow-queries.md index b15de63c630c7..aaab48e497eeb 100644 --- a/identify-slow-queries.md +++ b/identify-slow-queries.md @@ -101,6 +101,8 @@ The following fields are related to transaction execution: * `Write_keys`: The count of keys that the transaction writes to the Write CF in TiKV. * `Write_size`: The total size of the keys or values to be written when the transaction commits. * `Prewrite_region`: The number of TiKV Regions involved in the first phase (prewrite) of the two-phase transaction commit. Each Region triggers a remote procedure call. +* `Wait_prewrite_binlog_time`: The time used to write binlogs when a transaction is committed. +* `Resolve_lock_time`: The time to resolve or wait for the lock to be expired after a lock is encountered during a transaction commit. Memory usage fields: @@ -133,6 +135,12 @@ TiKV Coprocessor Task fields: * `Cop_wait_p90`: The P90 waiting time of cop-tasks. * `Cop_wait_max`: The maximum waiting time of cop-tasks. * `Cop_wait_addr`: The address of the cop-task whose waiting time is the longest. +* `Rocksdb_delete_skipped_count`: The number of scans on deleted keys during RocksDB reads. +* `Rocksdb_key_skipped_count`: The number of deleted (tombstone) keys that RocksDB encounters when scanning data. +* `Rocksdb_block_cache_hit_count`: The number of times RocksDB reads data from the block cache. +* `Rocksdb_block_read_count`: The number of times RocksDB reads data from the file system. +* `Rocksdb_block_read_byte`: The amount of data RocksDB reads from the file system. +* `Rocksdb_block_read_time`: The time RocksDB takes to read data from the file system. * `Cop_backoff_{backoff-type}_total_times`: The total times of backoff caused by an error. * `Cop_backoff_{backoff-type}_total_time`: The total time of backoff caused by an error. * `Cop_backoff_{backoff-type}_max_time`: The longest time of backoff caused by an error. @@ -140,6 +148,19 @@ TiKV Coprocessor Task fields: * `Cop_backoff_{backoff-type}_avg_time`: The average time of backoff caused by an error. * `Cop_backoff_{backoff-type}_p90_time`: The P90 percentile backoff time caused by an error. +`backoff-type` generally includes the following types: + +* `tikvRPC`: The backoff caused by failing to send RPC requests to TiKV. +* `tiflashRPC`: The backoff caused by failing to send RPC requests to TiFlash. +* `pdRPC`: The backoff caused by failing to send RPC requests to PD. +* `txnLock`: The backoff caused by lock conflicts. +* `regionMiss`: The backoff caused by that processing requests fails when the TiDB Region cache information is outdated after Regions are split or merged. +* `regionScheduling`: The backoff caused by that TiDB cannot process requests when Regions are being scheduled and the Leader is not selected. +* `tikvServerBusy`: The backoff caused by that the TiKV load is too high to handle new requests. +* `tiflashServerBusy`: The backoff caused by that the TiFlash load is too high to handle new requests. +* `tikvDiskFull`: The backoff caused by that the TiKV disk is full. +* `txnLockFast`: The backoff caused by that locks are encountered during data reads. + ## Related system variables * [`tidb_slow_log_threshold`](/system-variables.md#tidb_slow_log_threshold): Sets the threshold for the slow log. The SQL statement whose execution time exceeds this threshold is recorded in the slow log. The default value is 300 (ms).