---
title: ZooKeeper fields
description: ZooKeeper metrics collected by the four-letter monitoring commands. zookeeper contains the metrics reported by ZooKeeper commands. connections mntr contains...
url: https://www.elastic.co/elastic/docs-builder/docs/3028/reference/beats/metricbeat/exported-fields-zookeeper
products:
  - Beats
  - Metricbeat
applies_to:
  - Elastic Cloud Serverless: Generally available
  - Elastic Stack: Generally available
---

# ZooKeeper fields
ZooKeeper metrics collected by the four-letter monitoring commands.

## zookeeper

`zookeeper` contains the metrics reported by ZooKeeper commands.

## connection

connections
<definitions>
  <definition term="zookeeper.connection.interest_ops">
    Interest ops
    type: long
  </definition>
  <definition term="zookeeper.connection.queued">
    Queued connections
    type: long
  </definition>
  <definition term="zookeeper.connection.received">
    Received connections
    type: long
  </definition>
  <definition term="zookeeper.connection.sent">
    Connections sent
    type: long
  </definition>
</definitions>


## mntr

`mntr` contains the metrics reported by the four-letter `mntr` command.
<definitions>
  <definition term="zookeeper.mntr.approximate_data_size">
    Approximate size of ZooKeeper data.
    type: long
  </definition>
  <definition term="zookeeper.mntr.latency.avg">
    Average latency between ensemble hosts in milliseconds.
    type: long
  </definition>
  <definition term="zookeeper.mntr.ephemerals_count">
    Number of ephemeral znodes.
    type: long
  </definition>
  <definition term="zookeeper.mntr.followers">
    Number of followers seen by the current host (Up to ZooKeeper 3.5.9).
    type: long
  </definition>
  <definition term="zookeeper.mntr.max_file_descriptor_count">
    Maximum number of file descriptors allowed for the ZooKeeper process.
    type: long
  </definition>
  <definition term="zookeeper.mntr.latency.max">
    Maximum latency in milliseconds.
    type: long
  </definition>
  <definition term="zookeeper.mntr.latency.min">
    Minimum latency in milliseconds.
    type: long
  </definition>
  <definition term="zookeeper.mntr.num_alive_connections">
    Number of connections to ZooKeeper that are currently alive.
    type: long
  </definition>
  <definition term="zookeeper.mntr.open_file_descriptor_count">
    Number of file descriptors open by the ZooKeeper process.
    type: long
  </definition>
  <definition term="zookeeper.mntr.outstanding_requests">
    Number of outstanding requests that need to be processed by the cluster.
    type: long
  </definition>
  <definition term="zookeeper.mntr.packets.received">
    Number of ZooKeeper network packets received.
    type: long
  </definition>
  <definition term="zookeeper.mntr.packets.sent">
    Number of ZooKeeper network packets sent.
    type: long
  </definition>
  <definition term="zookeeper.mntr.pending_syncs">
    Number of pending syncs to carry out to ZooKeeper ensemble followers.
    type: long
  </definition>
  <definition term="zookeeper.mntr.server_state">
    Role in the ZooKeeper ensemble.
    type: keyword
  </definition>
  <definition term="zookeeper.mntr.synced_followers">
    Number of synced followers reported when a node server_state is leader.
    type: long
  </definition>
  <definition term="zookeeper.mntr.version">
    ZooKeeper version and build string reported.
    type: alias
    alias to: service.version
  </definition>
  <definition term="zookeeper.mntr.watch_count">
    Number of watches currently set on the local ZooKeeper process.
    type: long
  </definition>
  <definition term="zookeeper.mntr.znode_count">
    Number of znodes reported by the local ZooKeeper process.
    type: long
  </definition>
  <definition term="zookeeper.mntr.learners">
    Number of learners (either followers or observers) seen by the current host (From ZooKeeper 3.6.0)
    type: long
  </definition>
</definitions>


## server

server contains the metrics reported by the four-letter `srvr` command.
<definitions>
  <definition term="zookeeper.server.connections">
    Number of clients currently connected to the server
    type: long
  </definition>
  <definition term="zookeeper.server.latency.avg">
    Average amount of time taken for the server to respond to a client request
    type: long
  </definition>
  <definition term="zookeeper.server.latency.max">
    Maximum amount of time taken for the server to respond to a client request
    type: long
  </definition>
  <definition term="zookeeper.server.latency.min">
    Minimum amount of time taken for the server to respond to a client request
    type: long
  </definition>
  <definition term="zookeeper.server.mode">
    Mode of the server. In an ensemble, this may either be leader or follower. Otherwise, it is standalone
    type: keyword
  </definition>
  <definition term="zookeeper.server.node_count">
    Total number of nodes
    type: long
  </definition>
  <definition term="zookeeper.server.outstanding">
    Number of requests queued at the server. This exceeds zero when the server receives more requests than it is able to process
    type: long
  </definition>
  <definition term="zookeeper.server.received">
    Number of requests received by the server
    type: long
  </definition>
  <definition term="zookeeper.server.sent">
    Number of requests sent by the server
    type: long
  </definition>
  <definition term="zookeeper.server.version_date">
    Date of the Zookeeper release currently in use
    type: date
  </definition>
  <definition term="zookeeper.server.zxid">
    Unique value of the Zookeeper transaction ID. The zxid consists of an epoch and a counter. It is established by the leader and is used to determine the temporal ordering of changes
    type: keyword
  </definition>
  <definition term="zookeeper.server.count">
    Total transactions of the leader in epoch
    type: long
  </definition>
  <definition term="zookeeper.server.epoch">
    Epoch value of the Zookeeper transaction ID. An epoch signifies the period in which a server is a leader
    type: long
  </definition>
</definitions>