Aiven for ClickHouse® metrics exposed in Grafana®
Browse through metrics that are available via Grafana® for Aiven for ClickHouse® services.
Current counts
The following metrics are displayed on the monitoring dashboard as counts reflecting the current status:
Databases
: Number of databasesTables
: Number of tablesParts
: Total number of MergeTree table partsRows total
: Total number of rowsRunning Queries
: Total number of queries currently executedRunning Merges
: Number of merges currently executed in the backgroundParts Merged
: Number of times data parts of ReplicatedMergeTree tables were successfully mergedReadonly Tables
: Number of replicated tables that are currently in the read-only state due to re-initialization after ZooKeeper session loss or due to startup without ZooKeeper configured
Charts
The following metrics are displayed on the monitoring dashboard as charts reflecting data changes over time:
Connections
- Number of connections to the TCP server (clients with native interface), also included server-server distributed query connections
- Number of connections to the HTTP server
- Number of connections from other replicas to fetch parts
Queries
- Number of executed SELECT queries (includes internal/monitoring queries)
- Number of executed INSERT queries
- Number of failed queries
Delayed Queries
- Number of INSERT queries that are throttled due to high number of active data parts for partition in a MergeTree table
- Number of queries that are stopped and waiting due to 'priority' setting
Replicated Part Fetches
- Number of data parts being checked for consistency
- Number of data parts being fetched from replica Each fetch consumes disk IO and inter-server network IO.
Miscellaneous
Running Merges
Merge operations reduce the number of parts and improve SELECT performance. Each merge consumes disk IO (read and write). A new part will be merged approximately 15 min after being inserted.Inserted Rows
: Number of rows INSERTed to all tablesInserted Bytes
: Number of bytes (uncompressed) INSERTed to all tablesMerged Rows
: Rows read for background merges (before merge)Merged: Data Read
: Uncompressed bytes that were read for background mergesCompressed Data Read
: Number of bytes before decompression read from compressed sourcesRows Delta
: Difference in number of rows between nodesParts
: Total number of MergeTree table parts. Each INSERT creates a new part.Replicated Part Merged