You can get essential statistics about your cluster in an easy-to-understand, tabular format using the compact and aligned text (CAT) API. The cat API is a human-readable interface that returns plain text instead of traditional JSON.
Using the cat API, you can answer questions like which node is the elected master, what state is the cluster in, how many documents are in each index, and so on.
To see the available operations in the cat API, use the following command:
You can also use the following string parameters with your query.
| ||Makes the output more verbose by adding headers to the columns. It also adds some formatting to help align each of the columns together. All examples on this page include the |
| ||Lists the default and other available headers for a given operation.|
| ||Limits the output to specific headers.|
| ||Outputs the result in JSON, YAML, or CBOR formats.|
| ||Sorts the output by the specified columns.|
To see what each column represents, use the
To see all the available headers, use the
To limit the output to a subset of headers, use the
Typically, for any operation you can find out what headers are available using the
?help parameter, and then use the
?h parameter to limit the output to only the headers that you care about.
Table of contents
- Field data
- Node attributes
- Pending tasks
- Thread pool
Lists the mapping of aliases to indices, plus routing and filtering information.
To limit the information to a specific alias, add the alias name after your query.
Lists the allocation of disk space for indices and the number of shards on each node. Default request:
Lists the number of documents in your cluster.
To see the number of documents in a specific index, add the index name after your query.
Lists the memory size used by each field per node.
To limit the information to a specific field, add the field name after your query.
Lists the status of the cluster, how long the cluster has been up, the number of nodes, and other useful information that helps you analyze the health of your cluster.
Lists information related to indices—how much disk space they are using, how many shards they have, their health status, and so on.
To limit the information to a specific index, add the index name after your query.
Lists information that helps identify the elected master node.
Lists the attributes of custom nodes.
Lists node-level information, including node roles and load metrics.
A few important node metrics are
jdk, along with
Lists the progress of all pending tasks, including task priority and time in queue.
Lists the names, components, and versions of the installed plugins.
Lists all completed and ongoing index and shard recoveries.
To see only the recoveries of a specific index, add the index name after your query.
Lists all snapshot repositories and their types.
Lists Lucene segment-level information for each index.
To see only the information about segments of a specific index, add the index name after your query.
Lists the state of all primary and replica shards and how they are distributed.
To see only the information about shards of a specific index, add the index name after your query.
Lists all snapshots for a repository.
Lists the progress of all tasks currently running on your cluster.
Lists the names, patterns, order numbers, and version numbers of index templates.
Lists the active, queued, and rejected threads of different thread pools on each node.
To limit the information to a specific thread pool, add the thread pool name after your query.