Monitoring

Timeplus provides detailed metrics and states to monitor Materialized Views.
The Timeplus Console offers visualizations for these metrics and states, but you can also query them directly.

Metrics

The system.stream_metric_log stream records performance metrics such as events per second (eps) and megabytes per second (mbps) for Materialized Views, streams, external streams, and external tables.

Example:

SELECT 
    node_id, 
    database, 
    name, 
    (read_bytes * 1000) / elapsed_ms AS rbps,
    (read_rows * 1000) / elapsed_ms AS reps,
    (written_bytes * 1000) / elapsed_ms AS wbps,
    (written_rows * 1000) / elapsed_ms AS weps
FROM table(system.stream_metric_log) 
WHERE type = 'MaterializedView' 
  AND _tp_time > now() - 1h;

States

The system.stream_state_log stream contains detailed state information that can be used for monitoring and alerting.

Supported states include:

• last_error_message: Last error message of the Materialized View.
• recover_times: Number of recovery attempts.
• memory_usage: Current memory usage of the Materialized View.
• checkpoint_storage_size: Total size of checkpoint data.
• last_checkpoint_bytes: Checkpoint size (bytes) in the last epoch.
• last_checkpoint_elapsed_ms: Time taken (ms) for the last checkpoint.
• start_sn: Current start offset/sequence (Kafka partition or Timeplus shard).
• end_sn: Current end offset/sequence (Kafka partition or Timeplus shard).
• processed_sn: Current processed offset/sequence.
• ckpt_sn: Last checkpointed offset/sequence.
• processed_record_ts: Timestamp of the last processed record.

Example:

SELECT
    *
FROM
    table(system.stream_state_log)
WHERE
    dimension = 'materialized_view'
    AND state_name IN ('end_sn', 'processed_sn');

System Built-in Views

Timeplus provides built-in system views to help monitor Materialized Views:

• system.v_failed_mat_views: Tracks Materialized Views that have failed.
• system.v_mat_view_lags: Shows Materialized Views with processing lag.