---
title: "History Server"
weight: 3
type: docs
aliases:
  - /deployment/advanced/historyserver.html
  - /monitoring/historyserver.html
---
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# 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The HistoryServer allows you to query the status and statistics of completed jobs that have been archived by a JobManager.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:

```shell
# Start or stop the HistoryServer
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`.

```yaml
# Directory to upload completed job information
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`.

```yaml
# Monitor the following directories for completed jobs
historyserver.archive.fs.dir: hdfs:///completed-jobs

# Refresh every 10 seconds
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]({{< ref "docs/deployment/config" >}}#history-server).

## 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`]({{< ref "docs/deployment/config" >}}#historyserver-log-jobmanager-url-pattern)
and [`historyserver.log.taskmanager.url-pattern`]({{< ref "docs/deployment/config" >}}#historyserver-log-taskmanager-url-pattern)).
In this way, you can directly link from HistoryServer WebUI to logs of the relevant JobManager / TaskManagers.

```yaml
# HistoryServer will replace <jobid> with the relevant job id
historyserver.log.jobmanager.url-pattern: http://my.log-browsing.url/<jobid>

# HistoryServer will replace <jobid> and <tmid> with the relevant job id and taskmanager id
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`

{{< top >}}
