opensearch-docs-cn/_monitoring-your-cluster/pa/index.md

---
layout: default
title: Performance Analyzer
nav_order: 58
has_children: true
redirect_from:
  - /monitoring-plugins/pa/
  - /monitoring-plugins/pa/index/
---

# Performance analyzer

Performance analyzer is an agent and REST API that allows you to query numerous performance metrics for your cluster, including aggregations of those metrics. 

The performance analyzer plugin is installed by default in OpenSearch version 2.0 and higher.
{: .note }

## Performance analyzer installation and configuration

The following sections provide the steps for installing and configuring the performance analyzer plugin.

### Install performance analyzer

The performance analyzer plugin is included in the installation for [Docker]({{site.url}}{{site.baseurl}}/opensearch/install/docker/) and [tarball]({{site.url}}{{site.baseurl}}/opensearch/install/tar/). If you need to install the performance analyzer plugin manually, download the plugin from [Maven](https://search.maven.org/search?q=org.opensearch.plugin) and install the plugin using the standard [plugins install]({{site.url}}{{site.baseurl}}/opensearch/install/plugins/) process. Performance analyzer will run on each node in a cluster.

To start the performance analyzer root cause analysis (RCA) agent on a tarball installation, run the following command:
      
````bash
OPENSEARCH_HOME=~/opensearch-2.2.1 OPENSEARCH_JAVA_HOME=~/opensearch-2.2.1/jdk OPENSEARCH_PATH_CONF=~/opensearch-2.2.1/bin ./performance-analyzer-agent-cli
````

The following command enables the performance analyzer plugin and performance analyzer RCA agent:

````bash
curl -XPOST localhost:9200/_plugins/_performanceanalyzer/cluster/config -H 'Content-Type: application/json' -d '{"enabled": true}'
````

To shut down the performance analyzer RCA agent, run the following command:

````bash
kill $(ps aux | grep -i 'PerformanceAnalyzerApp' | grep -v grep | awk '{print $2}')
````

To disable the performance analyzer plugin, run the following command:

````bash
curl -XPOST localhost:9200/_plugins/_performanceanalyzer/cluster/config -H 'Content-Type: application/json' -d '{"enabled": false}'
````

To uninstall the performance analyzer plugin, run the following command:

````bash
bin/opensearch-plugin remove opensearch-performance-analyzer
````

### Configure performance analyzer

To configure the performance analyzer plugin, you will need to edit the `performance-analyzer.properties` configuration file in the `config/opensearch-performance-analyzer/` directory. Make sure to uncomment the line `#webservice-bind-host` and set it to `0.0.0.0`. You can reference the following example configuration.

````bash
# ======================== OpenSearch performance analyzer plugin config =========================

# NOTE: this is an example for Linux. Please modify the config accordingly if you are using it under other OS.

# WebService bind host; default to all interfaces
webservice-bind-host = 0.0.0.0

# Metrics data location
metrics-location = /dev/shm/performanceanalyzer/

# Metrics deletion interval (minutes) for metrics data.
# Interval should be between 1 to 60.
metrics-deletion-interval = 1

# If set to true, the system cleans up the files behind it. So at any point, we should expect only 2
# metrics-db-file-prefix-path files. If set to false, no files are cleaned up. This can be useful, if you are archiving
# the files and wouldn't like for them to be cleaned up.
cleanup-metrics-db-files = true

# WebService exposed by App's port
webservice-listener-port = 9600

# Metric DB File Prefix Path location
metrics-db-file-prefix-path = /tmp/metricsdb_

https-enabled = false

#Setup the correct path for certificates
#certificate-file-path = specify_path

#private-key-file-path = specify_path

# Plugin Stats Metadata file name, expected to be in the same location
plugin-stats-metadata = plugin-stats-metadata

# Agent Stats Metadata file name, expected to be in the same location
agent-stats-metadata = agent-stats-metadata
````
To start the performance analyzer RCA agent, run the following command.

````bash
OPENSEARCH_HOME=~/opensearch-2.2.1 OPENSEARCH_JAVA_HOME=~/opensearch-2.2.1/jdk OPENSEARCH_PATH_CONF=~/opensearch-2.2.1/bin ./performance-analyzer-agent-cli
````

### Storage

Performance analyzer uses `/dev/shm` for temporary storage. During heavy workloads on a cluster, performance analyzer can use up to 1 GB of space.

Docker, however, has a default `/dev/shm` size of 64 MB. To change this value, you can use the `docker run --shm-size 1gb` flag or [a similar setting in Docker Compose](https://docs.docker.com/compose/compose-file#shm_size).

If you're not using Docker, check the size of `/dev/shm` using `df -h`. The default value is probably plenty, but if you need to change its size, add the following line to `/etc/fstab`:

```bash
tmpfs /dev/shm tmpfs defaults,noexec,nosuid,size=1G 0 0
```

Then remount the file system:

```bash
mount -o remount /dev/shm
```

### Security

Performance analyzer supports encryption in transit for requests. It currently does *not* support client or server authentication for requests. To enable encryption in transit, edit `performance-analyzer.properties` in your `$OPENSEARCH_HOME` directory.

```bash
vi $OPENSEARCH_HOME/config/opensearch-performance-analyzer/performance-analyzer.properties
```

Change the following lines to configure encryption in transit. Note that `certificate-file-path` must be a certificate for the server, not a root certificate authority (CA).

````bash
https-enabled = true

#Setup the correct path for certificates
certificate-file-path = specify_path

private-key-file-path = specify_path
````

### Enable performance analyzer for RPM/YUM installations

If you installed OpenSearch from an RPM distribution, you can start and stop performance analyzer with `systemctl`.

```bash
# Start OpenSearch Performance Analyzer
sudo systemctl start opensearch-performance-analyzer.service
# Stop OpenSearch Performance Analyzer
sudo systemctl stop opensearch-performance-analyzer.service
```

## Example API query and response

The following is an example API query:
  
````bash
GET localhost:9600/_plugins/_performanceanalyzer/metrics/units
````

The following is an example response:

````json
{"Disk_Utilization":"%","Cache_Request_Hit":"count", 
"Refresh_Time":"ms","ThreadPool_QueueLatency":"count",
"Merge_Time":"ms","ClusterApplierService_Latency":"ms",
"PublishClusterState_Latency":"ms",
"Cache_Request_Size":"B","LeaderCheck_Failure":"count",
"ThreadPool_QueueSize":"count","Sched_Runtime":"s/ctxswitch","Disk_ServiceRate":"MB/s","Heap_AllocRate":"B/s","Indexing_Pressure_Current_Limits":"B",
"Sched_Waittime":"s/ctxswitch","ShardBulkDocs":"count",
"Thread_Blocked_Time":"s/event","VersionMap_Memory":"B",
"Master_Task_Queue_Time":"ms","IO_TotThroughput":"B/s",
"Indexing_Pressure_Current_Bytes":"B",
"Indexing_Pressure_Last_Successful_Timestamp":"ms",
"Net_PacketRate6":"packets/s","Cache_Query_Hit":"count",
"IO_ReadSyscallRate":"count/s","Net_PacketRate4":"packets/s","Cache_Request_Miss":"count",
"ThreadPool_RejectedReqs":"count","Net_TCP_TxQ":"segments/flow","Master_Task_Run_Time":"ms",
"IO_WriteSyscallRate":"count/s","IO_WriteThroughput":"B/s",
"Refresh_Event":"count","Flush_Time":"ms","Heap_Init":"B",
"Indexing_Pressure_Rejection_Count":"count",
"CPU_Utilization":"cores","Cache_Query_Size":"B",
"Merge_Event":"count","Cache_FieldData_Eviction":"count",
"IO_TotalSyscallRate":"count/s","Net_Throughput":"B/s",
"Paging_RSS":"pages",
"AdmissionControl_ThresholdValue":"count",
"Indexing_Pressure_Average_Window_Throughput":"count/s",
"Cache_MaxSize":"B","IndexWriter_Memory":"B",
"Net_TCP_SSThresh":"B/flow","IO_ReadThroughput":"B/s",
"LeaderCheck_Latency":"ms","FollowerCheck_Failure":"count",
"HTTP_RequestDocs":"count","Net_TCP_Lost":"segments/flow",
"GC_Collection_Event":"count","Sched_CtxRate":"count/s",
"AdmissionControl_RejectionCount":"count","Heap_Max":"B",
"ClusterApplierService_Failure":"count",
"PublishClusterState_Failure":"count",
"Merge_CurrentEvent":"count","Indexing_Buffer":"B",
"Bitset_Memory":"B","Net_PacketDropRate4":"packets/s",
"Heap_Committed":"B","Net_PacketDropRate6":"packets/s",
"Thread_Blocked_Event":"count","GC_Collection_Time":"ms",
"Cache_Query_Miss":"count","Latency":"ms",
"Shard_State":"count","Thread_Waited_Event":"count",
"CB_ConfiguredSize":"B","ThreadPool_QueueCapacity":"count",
"CB_TrippedEvents":"count","Disk_WaitTime":"ms",
"Data_RetryingPendingTasksCount":"count",
"AdmissionControl_CurrentValue":"count",
"Flush_Event":"count","Net_TCP_RxQ":"segments/flow",
"Shard_Size_In_Bytes":"B","Thread_Waited_Time":"s/event",
"HTTP_TotalRequests":"count",
"ThreadPool_ActiveThreads":"count",
"Paging_MinfltRate":"count/s","Net_TCP_SendCWND":"B/flow",
"Cache_Request_Eviction":"count","Segments_Total":"count",
"FollowerCheck_Latency":"ms","Heap_Used":"B",
"Master_ThrottledPendingTasksCount":"count",
"CB_EstimatedSize":"B","Indexing_ThrottleTime":"ms",
"Master_PendingQueueSize":"count",
"Cache_FieldData_Size":"B","Paging_MajfltRate":"count/s",
"ThreadPool_TotalThreads":"count","ShardEvents":"count",
"Net_TCP_NumFlows":"count","Election_Term":"count"}
````

## Root cause analysis

The [root cause analysis]({{site.url}}{{site.baseurl}}/monitoring-plugins/pa/rca/index/) (RCA) framework uses the information from performance analyzer to inform administrators of the root cause of performance and availability issues that their clusters might be experiencing.

### Enable the RCA framework

To enable the RCA framework, run the following command:

```bash
curl -XPOST http://localhost:9200/_plugins/_performanceanalyzer/rca/cluster/config -H 'Content-Type: application/json' -d '{"enabled": true}'
```

If you encounter the `curl: (52) Empty reply from server` response, run the following command to enable RCA:

```bash
curl -XPOST https://localhost:9200/_plugins/_performanceanalyzer/rca/cluster/config -H 'Content-Type: application/json' -d '{"enabled": true}' -u 'admin:admin' -k
```

### Example API query and response

To request all available RCAs, run the following command:

````bash
GET localhost:9600/_plugins/_performanceanalyzer/rca
````

To request a specific RCA, run the following command:

````bash
GET localhost:9600/_plugins/_performanceanalyzer/rca?name=HighHeapUsageClusterRCA
````

The following is an example response:

```json
{
  "HighHeapUsageClusterRCA": [{
    "RCA_name": "HighHeapUsageClusterRCA",
    "state": "unhealthy",
    "timestamp": 1587426650942,
    "HotClusterSummary": [{
      "number_of_nodes": 2,
      "number_of_unhealthy_nodes": 1,
      "HotNodeSummary": [{
        "host_address": "192.168.144.2",
        "node_id": "JtlEoRowSI6iNpzpjlbp_Q",
        "HotResourceSummary": [{
          "resource_type": "old gen",
          "threshold": 0.65,
          "value": 0.81827232588145373,
          "avg": NaN,
          "max": NaN,
          "min": NaN,
          "unit_type": "heap usage in percentage",
          "time_period_seconds": 600,
          "TopConsumerSummary": [{
              "name": "CACHE_FIELDDATA_SIZE",
              "value": 590702564
            },
            {
              "name": "CACHE_REQUEST_SIZE",
              "value": 28375
            },
            {
              "name": "CACHE_QUERY_SIZE",
              "value": 12687
            }
          ],
        }]
      }]
    }]
  }]
}
```

## Performance analyzer and RCA API references

### Related links

Further documentation on the use of performance analyzer and RCA can be found at the following links:

- [Performance analyzer API guide]({{site.url}}{{site.baseurl}}/monitoring-plugins/pa/api/).
- [RCA]({{site.url}}{{site.baseurl}}/monitoring-plugins/pa/rca/index/).
- [RCA API guide]({{site.url}}{{site.baseurl}}/monitoring-plugins/pa/rca/api/).
- [RFC: Root cause analysis](https://github.com/opensearch-project/performance-analyzer-rca/blob/main/docs/rfc-rca.pdf).