[[cat-nodes]]
== cat nodes

The `nodes` command shows the cluster topology. For example

[source,js]
--------------------------------------------------
GET /_cat/nodes?v
--------------------------------------------------
// CONSOLE

Might look like:

[source,txt]
--------------------------------------------------
ip        heap.percent ram.percent cpu load_1m load_5m load_15m node.role master name
127.0.0.1           65          99  42    3.07                  mdi       *      mJw06l1
--------------------------------------------------
// TESTRESPONSE[s/3.07/(\\d+\\.\\d+( \\d+\\.\\d+ (\\d+\\.\\d+)?)?)?/]
// TESTRESPONSE[s/65          99  42/\\d+ \\d+ \\d+/]
// TESTRESPONSE[s/[*]/[*]/ s/mJw06l1/.+/ non_json]

The first few columns (`ip`, `heap.percent`, `ram.percent`, `cpu`, `load_*`) tell
you where your nodes live and give a quick picture of performance stats.

The last (`node.role`, `master`, and `name`) columns provide ancillary
information that can often be useful when looking at the cluster as a whole,
particularly large ones.  How many master-eligible nodes do I have?

The `nodes` API accepts an additional URL parameter `full_id` accepting `true`
or `false`. The purpose of this parameter is to format the ID field (if
requested with `id` or `nodeId`) in its full length or in abbreviated form (the
default).

[float]
=== Columns

Below is an exhaustive list of the existing headers that can be
passed to `nodes?h=` to retrieve the relevant details in ordered
columns.  If no headers are specified, then those marked to Appear
by Default will appear. If any header is specified, then the defaults
are not used.

Aliases can be used in place of the full header name for brevity.
Columns appear in the order that they are listed below unless a
different order is specified (e.g., `h=pid,id` versus `h=id,pid`).

When specifying headers, the headers are not placed in the output
by default.  To have the headers appear in the output, use verbose
mode (`v`). The header name will match the supplied value (e.g.,
`pid` versus `p`).  For example:

[source,js]
--------------------------------------------------
GET /_cat/nodes?v&h=id,ip,port,v,m
--------------------------------------------------
// CONSOLE

Might look like:

["source","txt",subs="attributes,callouts"]
--------------------------------------------------
id   ip        port  v         m
veJR 127.0.0.1 59938 {version} *
--------------------------------------------------
// TESTRESPONSE[s/veJR/.+/ s/59938/\\d+/ s/[*]/[*]/ non_json]

[cols="<,<,<,<,<",options="header",subs="normal"]
|=======================================================================
|Header |Alias |Appear by Default |Description |Example
|`id` |`nodeId` |No |Unique node ID |k0zy
|`pid` |`p` |No |Process ID |13061
|`ip` |`i` |Yes |IP address |127.0.1.1
|`port` |`po` |No |Bound transport port |9300
|`http_address` |`http`| No |Bound http address | 127.0.0.1:9200
|`version` |`v` |No |Elasticsearch version |{version}
|`build` |`b` |No |Elasticsearch Build hash |5c03844
|`jdk` |`j` |No |Running Java version |1.8.0
|`disk.total` |`dt`, `diskTotal` |No |Total disk space| 458.3gb
|`disk.used` |`du`, `diskUsed` |No |Used disk space| 259.8gb
|`disk.avail` |`d`, `disk`, `diskAvail` |No |Available disk space |198.4gb
|`disk.used_percent` |`dup`, `diskUsedPercent` |No |Used disk space percentage |56.71
|`heap.current` |`hc`, `heapCurrent` |No |Used heap |311.2mb
|`heap.percent` |`hp`, `heapPercent` |Yes |Used heap percentage |7
|`heap.max` |`hm`, `heapMax` |No |Maximum configured heap |1015.6mb
|`ram.current` |`rc`, `ramCurrent` |No |Used total memory |513.4mb
|`ram.percent` |`rp`, `ramPercent` |Yes |Used total memory percentage |47
|`ram.max` |`rm`, `ramMax` |No |Total memory |2.9gb
|`file_desc.current` |`fdc`, `fileDescriptorCurrent` |No |Used file
descriptors |123
|`file_desc.percent` |`fdp`, `fileDescriptorPercent` |Yes |Used file
descriptors percentage |1
|`file_desc.max` |`fdm`, `fileDescriptorMax` |No |Maximum number of file
descriptors |1024
|`cpu` | |No |Recent system CPU usage as percent |12
|`load_1m` |`l` |No |Most recent load average |0.22
|`load_5m` |`l` |No |Load average for the last five minutes |0.78
|`load_15m` |`l` |No |Load average for the last fifteen minutes |1.24
|`uptime` |`u` |No |Node uptime |17.3m
|`node.role` |`r`, `role`, `nodeRole` |Yes |Master eligible node (m);
Data node (d); Ingest node (i); Coordinating node only (-) |mdi
|`master` |`m` |Yes |Elected master (*); Not elected master (-) |*
|`name` |`n` |Yes |Node name |I8hydUG
|`completion.size` |`cs`, `completionSize` |No |Size of completion |0b
|`fielddata.memory_size` |`fm`, `fielddataMemory` |No |Used fielddata
cache memory |0b
|`fielddata.evictions` |`fe`, `fielddataEvictions` |No |Fielddata cache
evictions |0
|`query_cache.memory_size` |`qcm`, `queryCacheMemory` |No |Used query
cache memory |0b
|`query_cache.evictions` |`qce`, `queryCacheEvictions` |No |Query
cache evictions |0
|`request_cache.memory_size` |`rcm`, `requestCacheMemory` |No | Used request
cache memory |0b
|`request_cache.evictions` |`rce`, `requestCacheEvictions` |No |Request
cache evictions |0
|`request_cache.hit_count` |`rchc`, `requestCacheHitCount` |No | Request
cache hit count |0
|`request_cache.miss_count` |`rcmc`, `requestCacheMissCount` |No | Request
cache miss count |0
|`flush.total` |`ft`, `flushTotal` |No |Number of flushes |1
|`flush.total_time` |`ftt`, `flushTotalTime` |No |Time spent in flush |1
|`get.current` |`gc`, `getCurrent` |No |Number of current get
operations |0
|`get.time` |`gti`, `getTime` |No |Time spent in get |14ms
|`get.total` |`gto`, `getTotal` |No |Number of get operations |2
|`get.exists_time` |`geti`, `getExistsTime` |No |Time spent in
successful gets |14ms
|`get.exists_total` |`geto`, `getExistsTotal` |No |Number of successful
get operations |2
|`get.missing_time` |`gmti`, `getMissingTime` |No |Time spent in failed
gets |0s
|`get.missing_total` |`gmto`, `getMissingTotal` |No |Number of failed
get operations |1
|`indexing.delete_current` |`idc`, `indexingDeleteCurrent` |No |Number
of current deletion operations |0
|`indexing.delete_time` |`idti`, `indexingDeleteTime` |No |Time spent in
deletions |2ms
|`indexing.delete_total` |`idto`, `indexingDeleteTotal` |No |Number of
deletion operations |2
|`indexing.index_current` |`iic`, `indexingIndexCurrent` |No |Number
of current indexing operations |0
|`indexing.index_time` |`iiti`, `indexingIndexTime` |No |Time spent in
indexing |134ms
|`indexing.index_total` |`iito`, `indexingIndexTotal` |No |Number of
indexing operations |1
|`indexing.index_failed` |`iif`, `indexingIndexFailed` |No |Number of
failed indexing operations |0
|`merges.current` |`mc`, `mergesCurrent` |No |Number of current
merge operations |0
|`merges.current_docs` |`mcd`, `mergesCurrentDocs` |No |Number of
current merging documents |0
|`merges.current_size` |`mcs`, `mergesCurrentSize` |No |Size of current
merges |0b
|`merges.total` |`mt`, `mergesTotal` |No |Number of completed merge
operations |0
|`merges.total_docs` |`mtd`, `mergesTotalDocs` |No |Number of merged
documents |0
|`merges.total_size` |`mts`, `mergesTotalSize` |No |Size of current
merges |0b
|`merges.total_time` |`mtt`, `mergesTotalTime` |No |Time spent merging
documents |0s
|`refresh.total` |`rto`, `refreshTotal` |No |Number of refreshes |16
|`refresh.time` |`rti`, `refreshTime` |No |Time spent in refreshes |91ms
|`script.compilations` |`scrcc`, `scriptCompilations` |No |Total script compilations |17
|`script.cache_evictions` |`scrce`, `scriptCacheEvictions` |No |Total compiled scripts evicted from cache |6
|`search.fetch_current` |`sfc`, `searchFetchCurrent` |No |Current fetch
phase operations |0
|`search.fetch_time` |`sfti`, `searchFetchTime` |No |Time spent in fetch
phase |37ms
|`search.fetch_total` |`sfto`, `searchFetchTotal` |No |Number of fetch
operations |7
|`search.open_contexts` |`so`, `searchOpenContexts` |No |Open search
contexts |0
|`search.query_current` |`sqc`, `searchQueryCurrent` |No |Current query
phase operations |0
|`search.query_time` |`sqti`, `searchQueryTime` |No |Time spent in query
phase |43ms
|`search.query_total` |`sqto`, `searchQueryTotal` |No |Number of query
operations |9
|`search.scroll_current` |`scc`, `searchScrollCurrent` |No |Open scroll contexts |2
|`search.scroll_time` |`scti`, `searchScrollTime` |No |Time scroll contexts held open|2m
|`search.scroll_total` |`scto`, `searchScrollTotal` |No |Completed scroll contexts |1
|`segments.count` |`sc`, `segmentsCount` |No |Number of segments |4
|`segments.memory` |`sm`, `segmentsMemory` |No |Memory used by
segments |1.4kb
|`segments.index_writer_memory` |`siwm`, `segmentsIndexWriterMemory` |No
|Memory used by index writer |18mb
|`segments.version_map_memory` |`svmm`, `segmentsVersionMapMemory` |No
|Memory used by version map |1.0kb
|`segments.fixed_bitset_memory` |`sfbm`, `fixedBitsetMemory` |No
|Memory used by fixed bit sets for nested object field types and type filters for types referred in `join` fields |1.0kb
|`suggest.current` |`suc`, `suggestCurrent` |No |Number of current suggest operations |0
|`suggest.time` |`suti`, `suggestTime` |No |Time spent in suggest |0
|`suggest.total` |`suto`, `suggestTotal` |No |Number of suggest operations |0
|=======================================================================