Aiven for ClickHouse® metrics exposed in Grafana®#
Browse through metrics that are available via Grafana® for Aiven for ClickHouse® services.
The following metrics are displayed on the monitoring dashboard as counts reflecting the current status:
Databases: Number of databases
Tables: Number of tables
Parts: Total number of MergeTree table parts
Rows total: Total number of rows
Running Queries: Total number of queries currently executed
Running Merges: Number of merges currently executed in the background
Parts Merged: Number of times data parts of ReplicatedMergeTree tables were successfully merged
Readonly 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
The following metrics are displayed on the monitoring dashboard as charts reflecting data changes over time:
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
Number of executed SELECT queries (includes internal/monitoring queries)
Number of executed INSERT queries
Number of failed 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.
Running MergesMerge 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 tables
Inserted Bytes: Number of bytes (uncompressed) INSERTed to all tables
Merged Rows: Rows read for background merges (before merge)
Merged: Data Read: Uncompressed bytes that were read for background merges
Compressed Data Read: Number of bytes before decompression read from compressed sources
Rows Delta: Difference in number of rows between nodes
Parts: Total number of MergeTree table parts. Each INSERT creates a new part.
Replicated Part Merged