THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
...
Class Metrics is the core of metrics system, there are MetricRegistryMetricGroup and MetricsReporter container in it. When the Metrics instance is initiating, the MetricRegistry MetricGroup is instantiated and metrics reporters are started.
...
| Code Block | ||
|---|---|---|
| ||
public class Metrics {
/** The registry that holds the metrics. */
private final MetricRegistry registry;
/** The metrics reporters container. */
private final List<MetricsReporter> reporters;
/** The metrics group. */
private final MetricGroup metricGroup;
/** Register metrics to MetricRegistryMetricGroup.
@param name The name of metric.
@param metric The metric to register.
*/
public void registerMetrics(String name, Metric metric) {}
} |
...
MetricGroup is a class responsible for metrics registering and tagging, there is a metrics container in it. It provides register method for each type of measurable metric, registering metrics will put metrics to the metrics container.
| Code Block | ||
|---|---|---|
| ||
public class MetricGroup {
/** Map of gauge metrics. */
private final Map<String, Gauge<?>> gauges = new HashMap<>();
/** Map of counter metrics. */
private final Map<String, Counter> counters = new HashMap<>();
/** Map Registerof gaugecounter metricmetrics. */
public void gauge(String name, private final Map<String, Histogram> histograms = new HashMap<>();
/** Register gauge metric. */
public void gauge(String name, Gauge gauge) {}
/** Register counter metric. */
public void counter(String name, Counter counter) {}
/** Register Addhistogram tag for metrics. */
public void addTag(String tag, String value) {}
}metric. */
public void histogram(String name, Histogram counter) {}
/** Add tag for metrics. */
public void addTag(Metric metric, String tag, String value) {}
} |
Paimon support to add tags for metrics, the tagged metrics will report metric value with tags. Table partition and bucket can be added as tag for some metrics. Like the number of files monitoring in committing / scan / compaction, users can monitor the files of different buckets to check the data skew, and by checking the commit duration of different buckets to see which unexpected bucket caused the long commit duration.
MetricsReporter
MetricsReporter is used to report metrics to external backend, Paimon will implement an out of box reporter as JMX `MetricsReporter`.
...
Take CommitMetrics as example, the CommitMetrics will be instantiated by FileStoreCommitImpl, then commit related metrics will be registered by MetricRegistry MetricGroup in singleton Metrics.
The Metrics has instance of MetricRegistry MetricGroup and MetricsReporters set. MetricRegistry MetricGroup maintains metrics map containers. Metrics registering is a process of putting metrics instances into the metric (gauge, counter) map container.
...
Metric Name | Description | Type | Tagged | Unit | Update at |
lastCommitDuration | The time it took to complete the last commit. | Gauge | Partition, Bucket | Ms | Timer starts before commit starting, update commit duration after the last commit finished. |
commitDuration | Distributions of the time taken by the last few commits. | Histogram | Partition, Bucket | Ms | Timer starts before commit starting, update commit duration after each commit finished. |
lastCommitAttempts | The number of attempts the last commit made. | Counter | Partition, Bucket | Number | Increment by 1 when trying to commit once, clear the counter after the last commit finished. |
lastTableFilesAdded | Number of added table files in last commit, including newly created data files and compacted after. | Gauge | Partition, Bucket | Number | Collecting changes from committables |
lastTableFilesDeleted | Number of deleted table files in last commit, which comes from compacted before. | Gauge | Partition, Bucket | Number | Collecting changes from committables |
lastTableFilesAppended | Number of appended table files in last commit, which means the newly created data files. | Gauge | Partition, Bucket | Number | Collecting changes from committables |
lastTableFilesCommitCompated | Number of compacted table files in last commit, including compacted before and after. | Gauge | Partition, Bucket | Number | Collecting changes from committables |
lastChangelogFilesAppended | Number of appended changelog files in last commit | Gauge | Partition, Bucket | Number | Collecting changes from committables |
lastChangelogFileCommitCompacted | Number of compacted changelog files in last commit | Gauge | Partition, Bucket | Number | Collecting changes from committables |
totalTablesFiles | Number of total data files currently maintained on storage. | Counter | Partition, Bucket | Number | Collecting changes from committables |
totalChangelogFiles | Number of total changelog files currently maintained on storage. | Counter | Partition, Bucket | Number | Collecting changes from committables |
lastGeneratedSnapshots | Number of snapshot files generated in last commit, maybe 1 snapshot or 2 snapshots. | Gauge | Partition, Bucket | Number | After collecting changes from committables |
totalSnapshots | Number of currently retained total snapshots. | Counter | none | Number | When trying to commit, the counter will increment by the number of snapshots generated When expiring snapshots, the counter will decrement by the number of expiring snapshots. |
lastTotalRecordsAppended | Total records count in last commit with APPEND commit kind | Gauge | none | Number | Preparing snapshot file with APPEND commit kind |
lastDeltaRecordsAppended | Delta records count in last commit with APPEND commit kind | Gauge | Partition, Bucket | Number | Preparing snapshot file with APPEND commit kind |
lastChangelogRecordsAppended | Changelog records count in last commit with APPEND commit kind | Gauge | Partition, Bucket | Number | Preparing snapshot file with APPEND commit kind |
lastTotalRecordsCommitCompated | Total records count in last commit with COMPACT commit kind | Gauge | Partition, Bucket | Number | Preparing snapshot file with COMPACT commit kind |
lastDeltaRecordsCommitCompated | Delta records count in last commit with COMPACT commit kind | Gauge | Partition, Bucket | Number | Preparing snapshot file with COMPACT commit kind |
lastChangelogRecordsCommitCompated | Changelog records count in last commit with COMPACT commit kind | GaugeGauge | Partition, Bucket | Number | Preparing snapshot file with COMPACT commit kind |
lastPartitionsWritten | Number of partitions written in last commit | Gauge | none | Number | After collecting changes from committables |
lastBucketsWritten | Number of buckets written in last commit | Gauge | none | Number | After collecting changes from committables |
...
Metric Name | Description | Type | Tagged | Unit | Update at |
lastScanDuration | The time it took to complete the last scan planning. | Gauge | Partition, Bucket | Ms | Timer starts before the scan planning starts, update after the last scan planning operation finished |
scanDuration | Distributions of the time taken by the last few scan planning operations. | Histogram | Partition, Bucket | Ms | Timer starts before the scan planning starts, update after each planning finished |
lastScannedManifests | Number of scanned manifests files in the last scan planning. | Gauge | Partition, Bucket | Number | Scan planning |
lastScanSkippedManifests | Number of skipped manifests files in the last scan planning. | Gauge | Partition, Bucket | Number | Scan planning |
lastScanResultTableFiles | Number of result table files in the last scan planning. | Gauge | Partition, Bucket | Number | Scan planning |
lastScanGenerateSplits | Number of splits generated by the last scan planning. | Gauge | Partition, Bucket | Number | Scan planning |
CompactionMetrics
...
Metric Name | Description | Type | Tagged | Unit | Update at |
lastCompactionDuration | The time it took to complete the last compaction. | Gauge | Partition, Bucket | Ms | Timer starts before compaction, update after the last compaction finished |
compactionDuration | Distributions of the time taken by the last few compactions. | Histogram | Partition, Bucket | Ms | Timer starts before compaction, update after each compaction finished |
lastTableFilesCompactedBefore | Number of deleted files in last compaction | Gauge | Partition, Bucket | Number | After getting compaction result. |
lastTableFilesCompactedAfter | Number of added files in last compaction | Gauge | Partition, Bucket | Number | After getting compaction result. |
lastChangelogFilesCompacted | Number of changelog files compacted in last compaction | Gauge | Partition, Bucket | Number | After getting compaction result. |
lastSortedRuns | Number of total sorted runs of all levels at last compaction | Gauge | Partition, Bucket | Number | Updating levels after getting compaction result. |
lastLevel0Files | Number of files at level 0 at last compaction | Gauge | Partition, Bucket | Number | Updating levels after getting compaction result. |
...