History Server

Flink has a history server that can be used to query the statistics of completed jobs after the corresponding Flink cluster has been shut down.

Furthermore, it exposes a REST API that accepts HTTP requests and responds with JSON data.

Overview

The HistoryServer allows you to query the status and statistics of completed jobs that have been archived by a JobManager.

After you have configured the HistoryServer and JobManager, you start and stop the HistoryServer via its corresponding startup script:

  1. # Start or stop the HistoryServer
  2. bin/historyserver.sh (start|start-foreground|stop)

By default, this server binds to localhost and listens at port 8082.

Currently, you can only run it as a standalone process.

Configuration

The configuration keys jobmanager.archive.fs.dir and historyserver.archive.fs.refresh-interval need to be adjusted for archiving and displaying archived jobs.

JobManager

The archiving of completed jobs happens on the JobManager, which uploads the archived job information to a file system directory. You can configure the directory to archive completed jobs in flink-conf.yaml by setting a directory via jobmanager.archive.fs.dir.

  1. # Directory to upload completed job information
  2. jobmanager.archive.fs.dir: hdfs:///completed-jobs

HistoryServer

The HistoryServer can be configured to monitor a comma-separated list of directories in via historyserver.archive.fs.dir. The configured directories are regularly polled for new archives; the polling interval can be configured via historyserver.archive.fs.refresh-interval.

  1. # Monitor the following directories for completed jobs
  2. historyserver.archive.fs.dir: hdfs:///completed-jobs
  4. # Refresh every 10 seconds
  5. historyserver.archive.fs.refresh-interval: 10000

The contained archives are downloaded and cached in the local filesystem. The local directory for this is configured via historyserver.web.tmpdir.

Check out the configuration page for a complete list of configuration options.

Log Integration

Flink does not provide built-in methods for archiving logs of completed jobs. However, if you already have log archiving and browsing services, you can configure HistoryServer to integrate them (via historyserver.log.jobmanager.url-pattern and historyserver.log.taskmanager.url-pattern). In this way, you can directly link from HistoryServer WebUI to logs of the relevant JobManager / TaskManagers.

  1. # HistoryServer will replace <jobid> with the relevant job id
  2. historyserver.log.jobmanager.url-pattern: http://my.log-browsing.url/<jobid>
  4. # HistoryServer will replace <jobid> and <tmid> with the relevant job id and taskmanager id
  5. historyserver.log.taskmanager.url-pattern: http://my.log-browsing.url/<jobid>/<tmid>

Available Requests

Below is a list of available requests, with a sample JSON response. All requests are of the sample form http://hostname:8082/jobs, below we list only the path part of the URLs.

Values in angle brackets are variables, for example http://hostname:port/jobs/<jobid>/exceptions will have to requested for example as http://hostname:port/jobs/7684be6004e4e955c2a558a9bc463f65/exceptions.

  • /config
  • /jobs/overview
  • /jobs/<jobid>
  • /jobs/<jobid>/vertices
  • /jobs/<jobid>/config
  • /jobs/<jobid>/exceptions
  • /jobs/<jobid>/accumulators
  • /jobs/<jobid>/vertices/<vertexid>
  • /jobs/<jobid>/vertices/<vertexid>/subtasktimes
  • /jobs/<jobid>/vertices/<vertexid>/taskmanagers
  • /jobs/<jobid>/vertices/<vertexid>/accumulators
  • /jobs/<jobid>/vertices/<vertexid>/subtasks/accumulators
  • /jobs/<jobid>/vertices/<vertexid>/subtasks/<subtasknum>
  • /jobs/<jobid>/vertices/<vertexid>/subtasks/<subtasknum>/attempts/<attempt>
  • /jobs/<jobid>/vertices/<vertexid>/subtasks/<subtasknum>/attempts/<attempt>/accumulators
  • /jobs/<jobid>/plan
  • /jobs/<jobid>/jobmanager/config
  • /jobs/<jobid>/jobmanager/environment
  • /jobs/<jobid>/jobmanager/log-url
  • /jobs/<jobid>/taskmanagers/<taskmanagerid>/log-url