B.6. Streaming Data

Documentation

VoltDB Home » Documentation » Administrator's Guide

B.6. Streaming Data

The following tables describe the metrics related to streaming data into and out of Volt, including import, export, and topics.

Table B.11. Import

MetricsTypeDescription
voltdb_​importer_​failure_​totalCounter

The number of import transactions that failed.

voltdb_​importer_​outstanding_​requests_​totalGauge

The number of records read from the import stream and waiting to be inserted into the database.

voltdb_​importer_​retries_​totalCounter

The number of attempts to replay failed transactions.

voltdb_​importer_​success_​totalCounter

The number of import transactions that succeeded.


Table B.12. Export

MetricsTypeDescription
voltdb_export_infoMetadata

Informational metric that contains metadata. Tags:

  • EXPORT_IS_ACTIVE - "True" if is enabled and not blocked and is master.

  • EXPORT_STATUS - The current status of the export connection.

  • "Active" - Queue is currently exporting to the target;

  • "Blocked" - There is a gap in the queue and export is waiting to see if the missing records become available when a missing node rejoins;

  • "Dropped" - either the source stream has been dropped from the schema or the export configuration has been removed from the configuration and queue is draining any remaining records.

voltdb_​export_​last_​acked_​timestamp_​secondsGauge

The timestamp when the last tuple was acknowledged as received by the target.

voltdb_​export_​last_​queued_​timestamp_​secondsGauge

The timestamp when the most recent tuple was added to the export queue for this partition.

voltdb_​export_​latency_​secondsHistogram

The distribution of time between when records are inserted, and then acknowledged by the target.

voltdb_​export_​queue_​gap_​totalGauge

The number of records missing from the queue for the current stream and partition.

voltdb_​export_​tuple_​count_​totalCounter

The total number of records queued to the export target since the queue was created.

voltdb_​export_​tuple_​pending_​totalGauge

The number of records still waiting to be written to or acknowledged by the target.


Table B.13. Topics

MetricsTypeDescription
voltdb_topic_infoMetadata

Informational metric with topic metadata. Tags:

  • TOPIC_STATUS -

  • "Stable" - The queue is complete;

  • "Backfilling" - records are missing but are being retrieved from other servers;

  • "Blocked" - records are missing from all copies of the partition;

  • "Orphaned" - the queue is no longer being served by this partition, but is saved in case other copies of the queue are blocked or backfilling and need the data. This is a transitional state and the queue is deleted as soon as no other copies need its records.

  • TOPIC_RETENTION_POLICY - The retention policy for this topic.

  • TOPIC_IS_MASTER - "True" or "False" indicating whether the current site is the master for the logical partition.

voltdb_​topic_​bytes_​fetched_​bytesGauge

The size of data sent to consumers for this partition and topic.

voltdb_​topic_​bytes_​on_​disk_​bytesGauge

The size of data stored on disk for this partition and topic.

voltdb_​topic_​error_​offsetGauge

If an error occurs while encoding a message for consumers, an error is returned to the consumer, the offset of the message is recoded here.

voltdb_​topic_​first_​offsetGauge

The value of the first offset currently available in the topic.

voltdb_​topic_​first_​offset_​timestamp_​secondsGauge

The timestamp when the first offset was inserted into the queue.

voltdb_​topic_​last_​offsetGauge

The value of the last offset in the topic.

voltdb_​topic_​last_​offset_​timestamp_​secondsGauge

The timestamp when the most recent message (the last offset) was inserted into the queue.

voltdb_​topic_​skipped_​rows_​totalGauge

The number of skipped rows that otherwise would cause an error. Only applies if the topic's option consumer.skip.errors is true.