Identify and resolve specific resource bottlenecks in RisingWave, including CPU, memory, storage, and more.
table_name
.
table_id(s)
shown in the storage metrics.
Example:
Get
: Used for point lookups (e.g., by HashAgg
executors).Iter
: Used for range/prefix scans (e.g., by HashJoin
executors).Get
durations for each state table.
Indicators:
avg
/ p99
duration consistently 10-100ms or higher.Iter
durations, divided into:
create_iter_time
: Time to initialize the storage iterator (fetching metadata, pruning files, initial seek).pure_scan_time
: Time spent scanning data within the iterator.p99
duration consistently 10-100ms or higher.processed
: Visible keys processed.skip_delete
: Tombstone keys encountered (marked for deletion).skip_multi_version
: Stale keys encountered (older versions of data).skip_delete
and skip_multi_version
values indicate that the compaction process is lagging.meta_miss
: Should ideally be close to 0%.data_miss
: Represents misses that require access to the remote object store.meta_miss
is non-zero.data_miss
is high.blocked at requiring memory
in CN logs. If it shows up, some state table writes are waiting for the shared buffer quota to be released.safe_epoch
and max_committed_epoch
is readable in a multi-version concurrency control (MVCC) manner. Compaction cannot reclaim data written above min_pinned_epoch
.
Indicators:
safe_epoch
/ min_pinned_epoch
and max_committed_epoch
.SHOW PROCESSLIST;
RECOVER;