Nodes Stats

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Nodes statistics

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The cluster nodes stats API allows to retrieve one or more (or all) of the cluster nodes statistics.

GET /_nodes/stats
GET /_nodes/nodeId1,nodeId2/stats

The first command retrieves stats of all the nodes in the cluster. The second command selectively retrieves nodes stats of only nodeId1 and nodeId2. All the nodes selective options are explained here.

By default, all stats are returned. You can limit this by combining any of indices, os, process, jvm, transport, http, fs, breaker and thread_pool. For example:

indices

Indices stats about size, document count, indexing and deletion times, search times, field cache size, merges and flushes

fs

File system information, data path, free disk space, read/write stats (see FS information)

http

HTTP connection information

jvm

JVM stats, memory pool information, garbage collection, buffer pools, number of loaded/unloaded classes

os

Operating system stats, load average, mem, swap (see OS statistics)

process

Process statistics, memory consumption, cpu usage, open file descriptors (see Process statistics)

thread_pool

Statistics about each thread pool, including current size, queue and rejected tasks

transport

Transport statistics about sent and received bytes in cluster communication

breaker

Statistics about the field data circuit breaker

discovery

Statistics about the discovery

ingest

Statistics about ingest preprocessing

adaptive_selection

Statistics about adaptive replica selection. See adaptive selection statistics.

# return just indices
GET /_nodes/stats/indices

# return just os and process
GET /_nodes/stats/os,process

# return just process for node with IP address 10.0.0.1
GET /_nodes/10.0.0.1/stats/process

All stats can be explicitly requested via /_nodes/stats/_all or /_nodes/stats?metric=_all.

FS information

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The fs flag can be set to retrieve information that concern the file system:

fs.timestamp
Last time the file stores statistics have been refreshed
fs.total.total_in_bytes
Total size (in bytes) of all file stores
fs.total.free_in_bytes
Total number of unallocated bytes in all file stores
fs.total.available_in_bytes
Total number of bytes available to this Java virtual machine on all file stores. Depending on OS or process level restrictions, this might appear less than fs.total.free_in_bytes. This is the actual amount of free disk space the Elasticsearch node can utilise.
fs.data
List of all file stores
fs.data.path
Path to the file store
fs.data.mount
Mount point of the file store (ex: /dev/sda2)
fs.data.type
Type of the file store (ex: ext4)
fs.data.total_in_bytes
Total size (in bytes) of the file store
fs.data.free_in_bytes
Total number of unallocated bytes in the file store
fs.data.available_in_bytes
Total number of bytes available to this Java virtual machine on this file store
fs.io_stats.devices (Linux only)
Array of disk metrics for each device that is backing an Elasticsearch data path. These disk metrics are probed periodically and averages between the last probe and the current probe are computed.
fs.io_stats.devices.device_name (Linux only)
The Linux device name.
fs.io_stats.devices.operations (Linux only)
The total number of read and write operations for the device completed since starting Elasticsearch.
fs.io_stats.devices.read_operations (Linux only)
The total number of read operations for the device completed since starting Elasticsearch.
fs.io_stats.devices.write_operations (Linux only)
The total number of write operations for the device completed since starting Elasticsearch.
fs.io_stats.devices.read_kilobytes (Linux only)
The total number of kilobytes read for the device since starting Elasticsearch.
fs.io_stats.devices.write_kilobytes (Linux only)
The total number of kilobytes written for the device since starting Elasticsearch.
fs.io_stats.operations (Linux only)
The total number of read and write operations across all devices used by Elasticsearch completed since starting Elasticsearch.
fs.io_stats.read_operations (Linux only)
The total number of read operations for across all devices used by Elasticsearch completed since starting Elasticsearch.
fs.io_stats.write_operations (Linux only)
The total number of write operations across all devices used by Elasticsearch completed since starting Elasticsearch.
fs.io_stats.read_kilobytes (Linux only)
The total number of kilobytes read across all devices used by Elasticsearch since starting Elasticsearch.
fs.io_stats.write_kilobytes (Linux only)
The total number of kilobytes written across all devices used by Elasticsearch since starting Elasticsearch.

Operating System statistics

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The os flag can be set to retrieve statistics that concern the operating system:

os.timestamp
Last time the operating system statistics have been refreshed
os.cpu.percent
Recent CPU usage for the whole system, or -1 if not supported
os.cpu.load_average.1m
One-minute load average on the system (field is not present if one-minute load average is not available)
os.cpu.load_average.5m
Five-minute load average on the system (field is not present if five-minute load average is not available)
os.cpu.load_average.15m
Fifteen-minute load average on the system (field is not present if fifteen-minute load average is not available)
os.mem.total_in_bytes
Total amount of physical memory in bytes
os.mem.free_in_bytes
Amount of free physical memory in bytes
os.mem.free_percent
Percentage of free memory
os.mem.used_in_bytes
Amount of used physical memory in bytes
os.mem.used_percent
Percentage of used memory
os.swap.total_in_bytes
Total amount of swap space in bytes
os.swap.free_in_bytes
Amount of free swap space in bytes
os.swap.used_in_bytes
Amount of used swap space in bytes
os.cgroup.cpuacct.control_group (Linux only)
The cpuacct control group to which the Elasticsearch process belongs
os.cgroup.cpuacct.usage_nanos (Linux only)
The total CPU time (in nanoseconds) consumed by all tasks in the same cgroup as the Elasticsearch process
os.cgroup.cpu.control_group (Linux only)
The cpu control group to which the Elasticsearch process belongs
os.cgroup.cpu.cfs_period_micros (Linux only)
The period of time (in microseconds) for how regularly all tasks in the same cgroup as the Elasticsearch process should have their access to CPU resources reallocated.
os.cgroup.cpu.cfs_quota_micros (Linux only)
The total amount of time (in microseconds) for which all tasks in the same cgroup as the Elasticsearch process can run during one period os.cgroup.cpu.cfs_period_micros
os.cgroup.cpu.stat.number_of_elapsed_periods (Linux only)
The number of reporting periods (as specified by os.cgroup.cpu.cfs_period_micros) that have elapsed
os.cgroup.cpu.stat.number_of_times_throttled (Linux only)
The number of times all tasks in the same cgroup as the Elasticsearch process have been throttled.
os.cgroup.cpu.stat.time_throttled_nanos (Linux only)
The total amount of time (in nanoseconds) for which all tasks in the same cgroup as the Elasticsearch process have been throttled.
os.cgroup.memory.control_group (Linux only)
The memory control group to which the Elasticsearch process belongs
os.cgroup.memory.limit_in_bytes (Linux only)
The maximum amount of user memory (including file cache) allowed for all tasks in the same cgroup as the Elasticsearch process. This value can be too big to store in a long, so is returned as a string so that the value returned can exactly match what the underlying operating system interface returns. Any value that is too large to parse into a long almost certainly means no limit has been set for the cgroup.
os.cgroup.memory.usage_in_bytes (Linux only)
The total current memory usage by processes in the cgroup (in bytes) by all tasks in the same cgroup as the Elasticsearch process. This value is stored as a string for consistency with os.cgroup.memory.limit_in_bytes.

For the cgroup stats to be visible, cgroups must be compiled into the kernel, the cpu and cpuacct cgroup subsystems must be configured and stats must be readable from /sys/fs/cgroup/cpu and /sys/fs/cgroup/cpuacct.

Process statistics

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The process flag can be set to retrieve statistics that concern the current running process:

process.timestamp
Last time the process statistics have been refreshed
process.open_file_descriptors
Number of opened file descriptors associated with the current process, or -1 if not supported
process.max_file_descriptors
Maximum number of file descriptors allowed on the system, or -1 if not supported
process.cpu.percent
CPU usage in percent, or -1 if not known at the time the stats are computed
process.cpu.total_in_millis
CPU time (in milliseconds) used by the process on which the Java virtual machine is running, or -1 if not supported
process.mem.total_virtual_in_bytes
Size in bytes of virtual memory that is guaranteed to be available to the running process

Indices statistics

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You can get information about indices stats on node, indices, or shards level.

# Fielddata summarised by node
GET /_nodes/stats/indices/fielddata?fields=field1,field2

# Fielddata summarised by node and index
GET /_nodes/stats/indices/fielddata?level=indices&fields=field1,field2

# Fielddata summarised by node, index, and shard
GET /_nodes/stats/indices/fielddata?level=shards&fields=field1,field2

# You can use wildcards for field names
GET /_nodes/stats/indices/fielddata?fields=field*

Supported metrics are:

  • completion
  • docs
  • fielddata
  • flush
  • get
  • indexing
  • merge
  • query_cache
  • recovery
  • refresh
  • request_cache
  • search
  • segments
  • store
  • translog
  • warmer

Search groups

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You can get statistics about search groups for searches executed on this node.

# All groups with all stats
GET /_nodes/stats?groups=_all

# Some groups from just the indices stats
GET /_nodes/stats/indices?groups=foo,bar

Ingest statistics

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The ingest flag can be set to retrieve statistics that concern ingest:

ingest.total.count
The total number of document ingested during the lifetime of this node
ingest.total.time_in_millis
The total time spent on ingest preprocessing documents during the lifetime of this node
ingest.total.current
The total number of documents currently being ingested.
ingest.total.failed
The total number ingest preprocessing operations failed during the lifetime of this node

On top of these overall ingest statistics, these statistics are also provided on a per pipeline basis.

Adaptive selection statistics

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The adaptive_selection flag can be set to retrieve statistics that concern adaptive replica selection. These statistics are keyed by node. For each node:

adaptive_selection.outgoing_searches
The number of outstanding search requests from the node these stats are for to the keyed node.
avg_queue_size
The exponentially weighted moving average queue size of search requests on the keyed node.
avg_service_time_ns
The exponentially weighted moving average service time of search requests on the keyed node.
avg_response_time_ns
The exponentially weighted moving average response time of search requests on the keyed node.
rank
The rank of this node; used for shard selection when routing search requests.