THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
| Discussion thread | https://lists.apache.org/thread/h2lgqgrvcptzj3c8q4cjzv5jopgtwx9o |
|---|---|
| Vote thread | TBDhttps://lists.apache.org/thread/09lfq4j7w23h6o1lmywl6k9691sqykhm |
| ISSUE | https://github.com/apache/incubator-paimon/issues/742 |
| Release | TBD0.6 |
Motivation
Currently Paimon runs without monitoring and metrics out of box. In the production environment, users need to know how their Paimon Table behaves like what is the commit duration, how many files each commit added or deleted, the status of compaction operation, the duration of scan query, lag of streaming reading and so on. So we need to introduce a metrics system and more metrics for Paimon.
...
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 registrymetrics that holds the metricsreporters container. */
private final MetricRegistry registry;
List<MetricsReporter> reporters = new ArrayList<>();
/** The metrics reporters containergroup. */
private final List<MetricsReporter> reporters; List<MetricGroup> metricGroups = new ArrayList<>();
/** Add Thea metrics groupreporter. */
private final MetricGroup metricGrouppublic void addReporter(MetricsReporter reporter) {};
/** RegisterAdd metricsa tometric MetricRegistrygroup. */
@parampublic namevoid The name of metric.
@param metric The metric to register.
addGroup(MetricGroup group) {};
/** Get metrics reporters. */
public voidList<MetricsReporter> registerMetrics(String name, Metric metricgetReporters() {}
} |
MetricGroup
;
/** Get metric groups. */
public List<MetricGroup> getMetricGroups() {};
} |
MetricGroup
MetricGroup 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 classinterface MetricGroup { /** Map ofRegister gauge metricsmetric. */ public void private final Map<String, Gauge<?>> gauges = new HashMap<>(); gauge(String name, Gauge gauge) {} /** MapRegister of counter metricsmetric. */ public void private final Map<Stringcounter(String name, Counter>Counter counters = new HashMap<>();counter) {} /** Register gaugehistogram metric. */ public void gaugehistogram(String name, GaugeHistogram gaugecounter) {} /** Register counter metric. */ public void counter(String name, Counter counter) {} /** Add tag for metrics. */ public void addTag(String tag, String value) {} }} |
Paimon support to add tags for metric groups, tags is likely to scopes in Flink's metric group. The tagged metrics group will report metric value with tags as a part of prefix of the metric name.
Table partition and bucket can be added as tag for some metric groups. 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 compaction duration of different buckets to see which unexpected bucket caused the long compaction duration.
MetricsReporter
MetricsReporter is used to report metrics to external backend, Paimon will implement an out of box reporter as JMX `MetricsReporter` MetricsReporter .
| Code Block | ||
|---|---|---|
| ||
public interface MetricsReporter {
/** Configure reporter after instantiating it.*/
void open();
/** Closes this reporter. */
void close();
/** Report the current measurements. This method is called periodically by the Metrics. */
void report();
} |
...
| draw.io Diagram | ||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Metrics Registering
Take CommitMetrics as example, the CommitMetrics will be instantiated by FileStoreCommitImpl, then commit related metrics will be registered by MetricRegistry the corresponding MetricGroup in singleton the Metrics instance.
The Metrics has instance of MetricRegistry MetricGroups 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.
...
| Code Block | ||
|---|---|---|
| ||
public class CommitMetrics {
private Metrics metrics;
private final String final String LAST_COMMIT_DURATION_METRIC = "lastCommitDuration";
...
private void registerCommitMetrics(Metrics metrics) {
metrics.gauge(COMMIT_DURATION_METRIC, new CommitDurationTimer());
...
}
...
} |
CommitMetrics list includes commit duration, counter of files / records etc.
private final Map<Integer, BucketMetricGroup> bucketMetricGroups = new HashMap<>();
private final Map<BinaryRow, PartitionMetricGroup> partitionMetricGroups = new HashMap<>();
private final MetricGroup genericMetricGroup;
private void registerGenericCommitMetrics() {
group.gauge(LAST_COMMIT_DURATION_METRIC, new CommitDurationGauge());
...
}
private void registerTaggedCommitMetrics() {
if(isNewBucket()) {
registerTaggedMetrics();
}
if(isNewBucket()) {
registerTaggedMetrics();
}
}
} |
CommitMetrics list includes commit duration, counter of files / records etc.
Metric Name | Description | Type | Tagged | Unit | Update at | |||||||||
lastCommitDuration | The time it took to complete the last commit. | Gauge | none | Ms | Timer starts | |||||||||
Metric Name | Description | Type | Unit | Update at | ||||||||||
lastCommitDuration | The time it took to complete the last commit. | Gauge | 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 | none | Ms | Timer starts before commit starting, update commit duration after each commit finished. | |||||||||
lastCommitAttempts | The number of attempts the last commit made. | Gauge | Counternone | 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 | Number | Collecting changes from committables | ||||||||||
lastTableFilesDeleted | Number of deleted table files in last commit, which comes from compacted before. | Gauge | Number | Collecting changes from committables | ||||||||||
. | ||||||||||||||
lastTableFilesAddedlastTableFilesAppended | Number of appended added table files in last commit, which means the including newly created data files and compacted after. | Gauge | none | Number | Collecting changes from committables | |||||||||
lastTableFilesCommitCompatedlastTableFilesDeleted | Number of compacted deleted table files in last commit, including which comes from compacted before and after. | Gauge | none | Number | Collecting changes from committables | |||||||||
lastChangelogFilesAppendedlastTableFilesAppended | Number of appended changelog table files in last commit | Gauge | Number | Collecting changes from committables | lastChangelogFileCommitCompacted | Number of compacted changelog files in last commit | , which means the newly created data files. | Gauge | noneGauge | Number | Collecting changes from committables | |||
totalTablesFileslastTableFilesCommitCompated | Number of total data files currently maintained on storage.compacted table files in last commit, including compacted before and after. | Gauge | noneCounter | Number | Collecting changes from committables | |||||||||
totalChangelogFileslastChangelogFilesAppended | Number of total appended changelog files currently maintained on storage.in last commit | Gauge | noneCounter | Number | Collecting changes from committables | |||||||||
lastGeneratedSnapshotslastChangelogFileCommitCompacted | Number of snapshot compacted changelog files generated in last commit, maybe 1 snapshot or 2 snapshots. | Gauge | none | Number | After collecting Collecting changes from committables | |||||||||
totalSnapshotslastGeneratedSnapshots | Number of currently retained total snapshots. | Counter | 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. | snapshot files generated in last commit, maybe 1 snapshot or 2 snapshots. | Gauge | none | Number | After collecting changes from committables | lastTotalRecordsAppended | Total records count in last commit with APPEND commit kind | Gauge | Number | Preparing snapshot file with APPEND commit kind |
lastDeltaRecordsAppended | Delta records count in last commit with APPEND commit kind | Gauge | none | Number | Preparing snapshot file with APPEND commit kind | |||||||||
lastChangelogRecordsAppended | Changelog records count in last commit with APPEND commit kind | Gauge | none | Number | Preparing snapshot file with APPEND commit kindlastTotalRecordsCommitCompated | Total records count in last commit with COMPACT commit kind | ||||||||
Gauge | Number | Preparing snapshot file with COMPACT commit kind | lastDeltaRecordsCommitCompated | Delta records count in last commit with COMPACT commit kind | Gauge | none | Number | Preparing snapshot file with COMPACT commit kind | ||||||
lastChangelogRecordsCommitCompated | Changelog records count in last commit with COMPACT commit kind | Gauge | none | 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 |
...
| Code Block |
|---|
public class ScanMetrics { private Metrics metrics; { private final String LAST_SCAN_SKIPPED_FILESMANIFESTS_METRIC = "lastScanDurationlastScanSkippedManifests"; ... ... private final Map<Integer, BucketMetricGroup> bucketMetricGroups = new HashMap<>(); private final Map<BinaryRow, PartitionMetricGroup> partitionMetricGroups = new HashMap<>(); private void registerScanMetricsregisterTaggedScanMetrics(Metrics metrics) { if(isNewBucket()) { metrics.counter(SCAN_FILES_METRIC, new ScanFilesCounterregisterTaggedMetrics(); } if(isNewPartition()); { ... registerTaggedMetrics(); } ...} } |
ScanMetrics list includes duration, data files and manifest files counter.
Metric Name | Description | Type | Tagged | Unit | Update at |
lastScanDuration | The time it took to complete the last scan planning. | Gauge | none | 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 | none | 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 | none | Number | Scan planning |
lastScanSkippedManifests | Number of skipped manifests files in the last scan planning. | Gauge | none | Number | Scan planning |
lastScanResultTableFiles | Number of result table files in the last scan planning. | Gauge | none | Number | Scan planning |
CompactionMetrics
...
lastScanGenerateSplits
...
Number of splits generated by the last scan planning.
...
Gauge
...
Number
...
Scan planning
| Code Block |
|---|
public class CompactionMetrics {
private final String LAST_TABLE_FILES_COMPACTED_BEFORE_METRIC = "lastTableFilesCompactedBefore";
...
private final Map<Integer, BucketMetricGroup> bucketMetricGroups = new HashMap<>();
private final Map<BinaryRow, PartitionMetricGroup> partitionMetricGroups = new HashMap<>();
private void registerTaggedCompactionMetrics() {
if(isNewBucket()) {
registerTaggedMetrics();
}
if(isNewPartition()) {
registerTaggedMetrics();
}
}
|
CompactionMetrics
| Code Block |
|---|
public class CompactionMetrics {
private Metrics metrics;
private final String COMPACTED_FILES_METRIC = "lastCompactionDuration";
...
private void registerCompactionMetrics(Metrics metrics) {
metrics.counter(COMPACTED_FILES_METRIC, new CompactedFilesCounter());
...
}
...
} |
CompactionMetrics list includes duration, and counter of files, sorted runs etc.
Metric Name | Description | Type | Tagged | Unit | Update at |
lastCompactionDuration | The time it took to complete the last compaction. | Gauge | none | Ms | Timer starts before compaction, update after the last compaction finished |
compactionDuration | Distributions of the time taken by the last few compactions. | Histogram | none | Ms | Timer starts before compaction, update after each compaction finished |
lastTableFilesCompactedBefore | Number of deleted files in last compaction | Gauge | none | Number | After getting compaction result. |
lastTableFilesCompactedAfter | Number of added files in last compaction | Gauge | none | Number | After getting compaction result. |
lastChangelogFilesCompacted | Number of changelog files compacted in last compaction | Gauge | none | Number | After getting compaction result. |
lastSortedRunslastCompactOutputLevel | Number of total sorted runs of all levels at last compaction | Gauge | none | Number | Updating levels after getting compaction result. |
lastLevel0FileslastCompactFileSize | Number of files at level 0 at Sum of file size compacted in last compaction | Gauge | none | Number | Updating levels after getting compaction result. |
...