MyRocks Status Variables

MyRocks status variables provide details about the inner workings of the storage engine and they can be useful in tuning the storage engine to a particular environment.

You can view these variables and their values by running:

mysql> SHOW STATUS LIKE 'rocksdb%';

The following global status variables are available:

Name Var Type
rocksdb_rows_deleted Numeric
rocksdb_rows_inserted Numeric
rocksdb_rows_read Numeric
rocksdb_rows_updated Numeric
rocksdb_rows_expired Numeric
rocksdb_rows_filtered Numeric
rocksdb_system_rows_deleted Numeric
rocksdb_system_rows_inserted Numeric
rocksdb_system_rows_read Numeric
rocksdb_system_rows_updated Numeric
rocksdb_memtable_total Numeric
rocksdb_memtable_unflushed Numeric
rocksdb_queries_point Numeric
rocksdb_queries_range Numeric
rocksdb_covered_secondary_key_lookups Numeric
rocksdb_block_cache_add Numeric
rocksdb_block_cache_add_failures Numeric
rocksdb_block_cache_bytes_read Numeric
rocksdb_block_cache_bytes_write Numeric
rocksdb_block_cache_data_add Numeric
rocksdb_block_cache_data_bytes_insert Numeric
rocksdb_block_cache_data_hit Numeric
rocksdb_block_cache_data_miss Numeric
rocksdb_block_cache_filter_add Numeric
rocksdb_block_cache_filter_bytes_evict Numeric
rocksdb_block_cache_filter_bytes_insert Numeric
rocksdb_block_cache_filter_hit Numeric
rocksdb_block_cache_filter_miss Numeric
rocksdb_block_cache_hit Numeric
rocksdb_block_cache_index_add Numeric
rocksdb_block_cache_index_bytes_evict Numeric
rocksdb_block_cache_index_bytes_insert Numeric
rocksdb_block_cache_index_hit Numeric
rocksdb_block_cache_index_miss Numeric
rocksdb_block_cache_miss Numeric
rocksdb_block_cache_compressed_hit Numeric
rocksdb_block_cache_compressed_miss Numeric
rocksdb_bloom_filter_prefix_checked Numeric
rocksdb_bloom_filter_prefix_useful Numeric
rocksdb_bloom_filter_useful Numeric
rocksdb_bytes_read Numeric
rocksdb_bytes_written Numeric
rocksdb_compact_read_bytes Numeric
rocksdb_compact_write_bytes Numeric
rocksdb_compaction_key_drop_new Numeric
rocksdb_compaction_key_drop_obsolete Numeric
rocksdb_compaction_key_drop_user Numeric
rocksdb_flush_write_bytes Numeric
rocksdb_get_hit_l0 Numeric
rocksdb_get_hit_l1 Numeric
rocksdb_get_hit_l2_and_up Numeric
rocksdb_get_updates_since_calls Numeric
rocksdb_iter_bytes_read Numeric
rocksdb_memtable_hit Numeric
rocksdb_memtable_miss Numeric
rocksdb_no_file_closes Numeric
rocksdb_no_file_errors Numeric
rocksdb_no_file_opens Numeric
rocksdb_num_iterators Numeric
rocksdb_number_block_not_compressed Numeric
rocksdb_number_db_next Numeric
rocksdb_number_db_next_found Numeric
rocksdb_number_db_prev Numeric
rocksdb_number_db_prev_found Numeric
rocksdb_number_db_seek Numeric
rocksdb_number_db_seek_found Numeric
rocksdb_number_deletes_filtered Numeric
rocksdb_number_keys_read Numeric
rocksdb_number_keys_updated Numeric
rocksdb_number_keys_written Numeric
rocksdb_number_merge_failures Numeric
rocksdb_number_multiget_bytes_read Numeric
rocksdb_number_multiget_get Numeric
rocksdb_number_multiget_keys_read Numeric
rocksdb_number_reseeks_iteration Numeric
rocksdb_number_sst_entry_delete Numeric
rocksdb_number_sst_entry_merge Numeric
rocksdb_number_sst_entry_other Numeric
rocksdb_number_sst_entry_put Numeric
rocksdb_number_sst_entry_singledelete Numeric
rocksdb_number_stat_computes Numeric
rocksdb_number_superversion_acquires Numeric
rocksdb_number_superversion_cleanups Numeric
rocksdb_number_superversion_releases Numeric
rocksdb_rate_limit_delay_millis Numeric
rocksdb_row_lock_deadlocks Numeric
rocksdb_row_lock_wait_timeouts Numeric
rocksdb_snapshot_conflict_errors Numeric
rocksdb_stall_l0_file_count_limit_slowdowns Numeric
rocksdb_stall_locked_l0_file_count_limit_slowdowns Numeric
rocksdb_stall_l0_file_count_limit_stops Numeric
rocksdb_stall_locked_l0_file_count_limit_stops Numeric
rocksdb_stall_pending_compaction_limit_stops Numeric
rocksdb_stall_pending_compaction_limit_slowdowns Numeric
rocksdb_stall_memtable_limit_stops Numeric
rocksdb_stall_memtable_limit_slowdowns Numeric
rocksdb_stall_total_stops Numeric
rocksdb_stall_total_slowdowns Numeric
rocksdb_stall_micros Numeric
rocksdb_wal_bytes Numeric
rocksdb_wal_group_syncs Numeric
rocksdb_wal_synced Numeric
rocksdb_write_other Numeric
rocksdb_write_self Numeric
rocksdb_write_timedout Numeric
rocksdb_write_wal Numeric
variable rocksdb_rows_deleted

This variable shows the number of rows that were deleted from MyRocks tables.

variable rocksdb_rows_inserted

This variable shows the number of rows that were inserted into MyRocks tables.

variable rocksdb_rows_read

This variable shows the number of rows that were read from MyRocks tables.

variable rocksdb_rows_updated

This variable shows the number of rows that were updated in MyRocks tables.

variable rocksdb_rows_expired

This variable shows the number of expired rows in MyRocks tables.

variable rocksdb_rows_filtered

This variable shows the number of rows that were filtered out for TTL in MyRocks tables.

variable rocksdb_system_rows_deleted

This variable shows the number of rows that were deleted from MyRocks system tables.

variable rocksdb_system_rows_inserted

This variable shows the number of rows that were inserted into MyRocks system tables.

variable rocksdb_system_rows_read

This variable shows the number of rows that were read from MyRocks system tables.

variable rocksdb_system_rows_updated

This variable shows the number of rows that were updated in MyRocks system tables.

variable rocksdb_memtable_total

This variable shows the memory usage, in bytes, of all memtables.

variable rocksdb_memtable_unflushed

This variable shows the memory usage, in bytes, of all unflushed memtables.

variable rocksdb_queries_point

This variable shows the number of single row queries.

variable rocksdb_queries_range

This variable shows the number of multi/range row queries.

variable rocksdb_covered_secondary_key_lookups

This variable shows the number of lookups via secondary index that were able to return all fields requested directly from the secondary index when the secondary index contained a field that is only a prefix of the varchar column.

variable rocksdb_block_cache_add

This variable shows the number of blocks added to block cache.

variable rocksdb_block_cache_add_failures

This variable shows the number of failures when adding blocks to block cache.

variable rocksdb_block_cache_bytes_read

This variable shows the number of bytes read from cache.

variable rocksdb_block_cache_bytes_write

This variable shows the number of bytes written into cache.

variable rocksdb_block_cache_data_add

This variable shows the number of data blocks added to block cache.

variable rocksdb_block_cache_data_bytes_insert

This variable shows the number of bytes of data blocks inserted into cache.

variable rocksdb_block_cache_data_hit

This variable shows the number of cache hits when accessing the data block from the block cache.

variable rocksdb_block_cache_data_miss

This variable shows the number of cache misses when accessing the data block from the block cache.

variable rocksdb_block_cache_filter_add

This variable shows the number of filter blocks added to block cache.

variable rocksdb_block_cache_filter_bytes_evict

This variable shows the number of bytes of bloom filter blocks removed from cache.

variable rocksdb_block_cache_filter_bytes_insert

This variable shows the number of bytes of bloom filter blocks inserted into cache.

variable rocksdb_block_cache_filter_hit

This variable shows the number of times cache hit when accessing filter block from block cache.

variable rocksdb_block_cache_filter_miss

This variable shows the number of times cache miss when accessing filter block from block cache.

variable rocksdb_block_cache_hit

This variable shows the total number of block cache hits.

variable rocksdb_block_cache_index_add

This variable shows the number of index blocks added to block cache.

variable rocksdb_block_cache_index_bytes_evict

This variable shows the number of bytes of index block erased from cache.

variable rocksdb_block_cache_index_bytes_insert

This variable shows the number of bytes of index blocks inserted into cache.

variable rocksdb_block_cache_index_hit

This variable shows the total number of block cache index hits.

variable rocksdb_block_cache_index_miss

This variable shows the number of times cache hit when accessing index block from block cache.

variable rocksdb_block_cache_miss

This variable shows the total number of block cache misses.

variable rocksdb_block_cache_compressed_hit

This variable shows the number of hits in the compressed block cache.

variable rocksdb_block_cache_compressed_miss

This variable shows the number of misses in the compressed block cache.

variable rocksdb_bloom_filter_prefix_checked

This variable shows the number of times bloom was checked before creating iterator on a file.

variable rocksdb_bloom_filter_prefix_useful

This variable shows the number of times the check was useful in avoiding iterator creation (and thus likely IOPs).

variable rocksdb_bloom_filter_useful

This variable shows the number of times bloom filter has avoided file reads.

variable rocksdb_bytes_read

This variable shows the total number of uncompressed bytes read. It could be either from memtables, cache, or table files.

variable rocksdb_bytes_written

This variable shows the total number of uncompressed bytes written.

variable rocksdb_compact_read_bytes

This variable shows the number of bytes read during compaction

variable rocksdb_compact_write_bytes

This variable shows the number of bytes written during compaction.

variable rocksdb_compaction_key_drop_new

This variable shows the number of key drops during compaction because it was overwritten with a newer value.

variable rocksdb_compaction_key_drop_obsolete

This variable shows the number of key drops during compaction because it was obsolete.

variable rocksdb_compaction_key_drop_user

This variable shows the number of key drops during compaction because user compaction function has dropped the key.

variable rocksdb_flush_write_bytes

This variable shows the number of bytes written during flush.

variable rocksdb_get_hit_l0

This variable shows the number of Get() queries served by L0.

variable rocksdb_get_hit_l1

This variable shows the number of Get() queries served by L1.

variable rocksdb_get_hit_l2_and_up

This variable shows the number of Get() queries served by L2 and up.

variable rocksdb_get_updates_since_calls

This variable shows the number of calls to GetUpdatesSince function. Useful to keep track of transaction log iterator refreshes

variable rocksdb_iter_bytes_read

This variable shows the number of uncompressed bytes read from an iterator. It includes size of key and value.

variable rocksdb_memtable_hit

This variable shows the number of memtable hits.

variable rocksdb_memtable_miss

This variable shows the number of memtable misses.

variable rocksdb_no_file_closes

This variable shows the number of time file were closed.

variable rocksdb_no_file_errors

This variable shows number of errors trying to read in data from an sst file.

variable rocksdb_no_file_opens

This variable shows the number of time file were opened.

variable rocksdb_num_iterators

This variable shows the number of currently open iterators.

variable rocksdb_number_block_not_compressed

This variable shows the number of uncompressed blocks.

variable rocksdb_number_db_next

This variable shows the number of calls to next.

variable rocksdb_number_db_next_found

This variable shows the number of calls to next that returned data.

variable rocksdb_number_db_prev

This variable shows the number of calls to prev.

variable rocksdb_number_db_prev_found

This variable shows the number of calls to prev that returned data.

variable rocksdb_number_db_seek

This variable shows the number of calls to seek.

variable rocksdb_number_db_seek_found

This variable shows the number of calls to seek that returned data.

variable rocksdb_number_deletes_filtered

This variable shows the number of deleted records that were not required to be written to storage because key did not exist.

variable rocksdb_number_keys_read

This variable shows the number of keys read.

variable rocksdb_number_keys_updated

This variable shows the number of keys updated, if inplace update is enabled.

variable rocksdb_number_keys_written

This variable shows the number of keys written to the database.

variable rocksdb_number_merge_failures

This variable shows the number of failures performing merge operator actions in RocksDB.

variable rocksdb_number_multiget_bytes_read

This variable shows the number of bytes read during RocksDB MultiGet() calls.

variable rocksdb_number_multiget_get

This variable shows the number MultiGet() requests to RocksDB.

variable rocksdb_number_multiget_keys_read

This variable shows the keys read via MultiGet().

variable rocksdb_number_reseeks_iteration

This variable shows the number of times reseek happened inside an iteration to skip over large number of keys with same userkey.

variable rocksdb_number_sst_entry_delete

This variable shows the total number of delete markers written by MyRocks.

variable rocksdb_number_sst_entry_merge

This variable shows the total number of merge keys written by MyRocks.

variable rocksdb_number_sst_entry_other

This variable shows the total number of non-delete, non-merge, non-put keys written by MyRocks.

variable rocksdb_number_sst_entry_put

This variable shows the total number of put keys written by MyRocks.

variable rocksdb_number_sst_entry_singledelete

This variable shows the total number of single delete keys written by MyRocks.

variable rocksdb_number_stat_computes

This variable was removed in Percona Server 5.7.23-23.

variable rocksdb_number_superversion_acquires

This variable shows the number of times the superversion structure has been acquired in RocksDB, this is used for tracking all of the files for the database.

variable rocksdb_number_superversion_cleanups
variable rocksdb_number_superversion_releases
variable rocksdb_rate_limit_delay_millis

This variable was removed in Percona Server 5.7.23-23.

variable rocksdb_row_lock_deadlocks

This variable shows the total number of deadlocks that have been detected since the instance was started.

variable rocksdb_row_lock_wait_timeouts

This variable shows the total number of row lock wait timeouts that have been detected since the instance was started.

variable rocksdb_snapshot_conflict_errors

This variable shows the number of snapshot conflict errors occurring during write transactions that forces the transaction to rollback.

variable rocksdb_stall_l0_file_count_limit_slowdowns

This variable shows the slowdowns in write due to L0 being close to full.

variable rocksdb_stall_locked_l0_file_count_limit_slowdowns

This variable shows the slowdowns in write due to L0 being close to full and compaction for L0 is already in progress.

variable rocksdb_stall_l0_file_count_limit_stops

This variable shows the stalls in write due to L0 being full.

variable rocksdb_stall_locked_l0_file_count_limit_stops

This variable shows the stalls in write due to L0 being full and compaction for L0 is already in progress.

variable rocksdb_stall_pending_compaction_limit_stops

This variable shows the stalls in write due to hitting limits set for max number of pending compaction bytes.

variable rocksdb_stall_pending_compaction_limit_slowdowns

This variable shows the slowdowns in write due to getting close to limits set for max number of pending compaction bytes.

variable rocksdb_stall_memtable_limit_stops

This variable shows the stalls in write due to hitting max number of memTables allowed.

variable rocksdb_stall_memtable_limit_slowdowns

This variable shows the slowdowns in writes due to getting close to max number of memtables allowed.

variable rocksdb_stall_total_stops

This variable shows the total number of write stalls.

variable rocksdb_stall_total_slowdowns

This variable shows the total number of write slowdowns.

variable rocksdb_stall_micros

This variable shows how long (in microseconds) the writer had to wait for compaction or flush to finish.

variable rocksdb_wal_bytes

This variables shows the number of bytes written to WAL.

variable rocksdb_wal_group_syncs

This variable shows the number of group commit WAL file syncs that have occurred.

variable rocksdb_wal_synced

This variable shows the number of times WAL sync was done.

variable rocksdb_write_other

This variable shows the number of writes processed by another thread.

variable rocksdb_write_self

This variable shows the number of writes that were processed by a requesting thread.

variable rocksdb_write_timedout

This variable shows the number of writes ending up with timed-out.

variable rocksdb_write_wal

This variable shows the number of Write calls that request WAL.