Monitoring Cluster Metrics with Amazon CloudWatch
Interpreting Health Dashboards
The Instance health tab in the Amazon ES console uses box charts to provide ataglance visibility into the health of each Elasticsearch node.

Each colored box shows the range of values for the node over the specified time period.

Blue boxes represent values that are consistent with other nodes. Red boxes represent outliers.

The white line within each box shows the node's current value.

The “whiskers” on either side of each box show the minimum and maximum values for all nodes over the time period.
Amazon ES domains send performance metrics to Amazon CloudWatch every minute. If you use General Purpose or Magnetic EBS volumes, the EBS volume metrics update only every five minutes. To view these metrics, use the Cluster health and Instance health tabs in the Amazon Elasticsearch Service console. The metrics are provided at no extra charge.
If you make configuration changes to your domain, the list of individual instances in the Cluster health and Instance health tabs often double in size for a brief period before returning to the correct number. For an explanation of this behavior, see Configuration Changes.
All metrics are in the AWS/ES
namespace. Metrics for individual nodes are in
the ClientId, DomainName, NodeId
dimension. Cluster metrics are in the
PerDomain, PerClient Metrics
dimension. Some node metrics are aggregated
at the cluster level and thus included in both dimensions. The service archives metrics
for
two weeks before discarding them.
Cluster Metrics
Amazon Elasticsearch Service provides the following metrics for clusters.
Metric  Description 

ClusterStatus.green 
A value of 1 indicates that all index shards are allocated to nodes in the cluster. Relevant statistics: Maximum 
ClusterStatus.yellow 
A value of 1 indicates that the primary shards for all indices are
allocated to nodes in the cluster, but replica shards for at least one
index are not. For more information, see Yellow Cluster
Status.
Relevant statistics: Maximum 
ClusterStatus.red 
A value of 1 indicates that the primary and replica shards for at least one index are not allocated to nodes in the cluster. For more information, see Red Cluster Status. Relevant statistics: Maximum 
Nodes 
The number of nodes in the Amazon ES cluster, including dedicated master nodes and UltraWarm nodes. For more information, see Configuration Changes. Relevant statistics: Maximum 
SearchableDocuments 
The total number of searchable documents across all data nodes in the cluster. Relevant statistics: Minimum, Maximum, Average 
DeletedDocuments 
The total number of documents marked for deletion across all data nodes in the cluster. These documents no longer appear in search results, but Elasticsearch only removes deleted documents from disk during segment merges. This metric increases after delete requests and decreases after segment merges. Relevant statistics: Minimum, Maximum, Average 
CPUUtilization 
The percentage of CPU usage for data nodes in the cluster. Maximum shows the node with the highest CPU usage. Average represents all nodes in the cluster. This metric is also available for individual nodes. Relevant statistics: Maximum, Average 
FreeStorageSpace 
The free space for data nodes in the cluster. The Amazon ES console displays this value in GiB. The Amazon CloudWatch console displays it in MiB.
Relevant statistics: Minimum, Maximum, Average, Sum 
ClusterUsedSpace 
The total used space for the cluster. You must leave the period at one minute to get an accurate value. The Amazon ES console displays this value in GiB. The Amazon CloudWatch console displays it in MiB. Relevant statistics: Minimum, Maximum 
ClusterIndexWritesBlocked 
Indicates whether your cluster is accepting or blocking incoming write requests. A value of 0 means that the cluster is accepting requests. A value of 1 means that it is blocking requests. Some common factors include the following:
Relevant statistics: Maximum 
JVMMemoryPressure 
The maximum percentage of the Java heap used for all data nodes in the cluster. Amazon ES uses half of an instance's RAM for the Java heap, up to a heap size of 32 GiB. You can scale instances vertically up to 64 GiB of RAM, at which point you can scale horizontally by adding instances. See Recommended CloudWatch Alarms. Relevant statistics: Maximum 
AutomatedSnapshotFailure 
The number of failed automated snapshots for the cluster. A value
of Relevant statistics: Minimum, Maximum 
CPUCreditBalance 
The remaining CPU credits available for data nodes in the cluster. A CPU credit provides the performance of a full CPU core for one minute. For more information, see CPU credits in the Amazon EC2 Developer Guide. This metric is available only for the T2 instance types. Relevant statistics: Minimum 
KibanaHealthyNodes 
A health check for Kibana. A value of 1 indicates normal behavior. A value of 0 indicates that Kibana is inaccessible. In most cases, the health of Kibana mirrors the health of the cluster. Relevant statistics: Minimum 
KMSKeyError 
A value of 1 indicates that the KMS customer master key used to encrypt data at rest has been disabled. To restore the domain to normal operations, reenable the key. The console displays this metric only for domains that encrypt data at rest. Relevant statistics: Minimum, Maximum 
KMSKeyInaccessible 
A value of 1 indicates that the KMS customer master key used to encrypt data at rest has been deleted or revoked its grants to Amazon ES. You can't recover domains that are in this state. If you have a manual snapshot, though, you can use it to migrate the domain's data to a new domain. The console displays this metric only for domains that encrypt data at rest. Relevant statistics: Minimum, Maximum 
InvalidHostHeaderRequests 
The number of HTTP requests made to the Elasticsearch cluster that included an invalid (or missing) host header. Valid requests include the domain hostname as the host header value. Amazon ES rejects invalid requests for public access domains that don't have a restrictive access policy. We recommend applying a restrictive access policy to all domains. If you see large values for this metric, confirm that your Elasticsearch clients include the domain hostname (and not, for example, its IP address) in their requests. Relevant statistics: Sum 
ElasticsearchRequests 
The number of requests made to the Elasticsearch cluster. Relevant statistics: Sum 
2xx, 3xx, 4xx, 5xx 
The number of requests to the domain that resulted in the given HTTP response code (2xx, 3xx, 4xx, 5xx). Relevant statistics: Sum 
Dedicated Master Node Metrics
Amazon Elasticsearch Service provides the following metrics for dedicated master nodes.
Metric  Description 

MasterCPUUtilization 
The maximum percentage of CPU resources used by the dedicated master nodes. We recommend increasing the size of the instance type when this metric reaches 60 percent. Relevant statistics: Average 
MasterFreeStorageSpace 
This metric is not relevant and can be ignored. The service does not use master nodes as data nodes. 
MasterJVMMemoryPressure 
The maximum percentage of the Java heap used for all dedicated master nodes in the cluster. We recommend moving to a larger instance type when this metric reaches 85 percent. Relevant statistics: Maximum 
MasterCPUCreditBalance 
The remaining CPU credits available for dedicated master nodes in the cluster. A CPU credit provides the performance of a full CPU core for one minute. For more information, see CPU credits in the Amazon EC2 Developer Guide. This metric is available only for the T2 instance types. Relevant statistics: Minimum 
MasterReachableFromNode 
A health check for Failures mean that the master node stopped or is not reachable. They are usually the result of a network connectivity issue or AWS dependency problem. Relevant statistics: Minimum 
MasterSysMemoryUtilization 
The percentage of the master node's memory that is in use. Relevant statistics: Maximum 
EBS Volume Metrics
Amazon Elasticsearch Service provides the following metrics for EBS volumes.
Metric  Description 

ReadLatency 
The latency, in seconds, for read operations on EBS volumes. Relevant statistics: Minimum, Maximum, Average 
WriteLatency 
The latency, in seconds, for write operations on EBS volumes. Relevant statistics: Minimum, Maximum, Average 
ReadThroughput 
The throughput, in bytes per second, for read operations on EBS volumes. Relevant statistics: Minimum, Maximum, Average 
WriteThroughput 
The throughput, in bytes per second, for write operations on EBS volumes. Relevant statistics: Minimum, Maximum, Average 
DiskQueueDepth 
The number of pending input and output (I/O) requests for an EBS volume. Relevant statistics: Minimum, Maximum, Average 
ReadIOPS 
The number of input and output (I/O) operations per second for read operations on EBS volumes. Relevant statistics: Minimum, Maximum, Average 
WriteIOPS 
The number of input and output (I/O) operations per second for write operations on EBS volumes. Relevant statistics: Minimum, Maximum, Average 
Instance Metrics
Amazon Elasticsearch Service provides the following metrics for each instance in a domain. Amazon ES also aggregates these instance metrics to provide insight into overall cluster health. You can verify this behavior using the Data samples statistic in the console. Note that each metric in the following table has relevant statistics for the node and the cluster.
Different versions of Elasticsearch use different thread pools to process calls to
the
_index
API. Elasticsearch 1.5 and 2.3 use the index thread pool.
Elasticsearch 5.x, 6.0, and 6.2 use the bulk thread
pool. 6.3 and later use the write thread pool. Currently, the Amazon ES console
doesn't include a graph for the bulk thread pool.
Use GET _cluster/settings?include_defaults=true
to check thread pool
and queue sizes for your cluster.
Metric  Description 

IndexingLatency 
The average time, in milliseconds, that it takes a shard to complete an indexing operation. Relevant node statistics: Average Relevant cluster statistics: Average, Maximum 
IndexingRate 
The number of indexing operations per minute. A single call to the
Relevant node statistics: Average Relevant cluster statistics: Average, Maximum, Sum 
SearchLatency 
The average time, in milliseconds, that it takes a shard on a data node to complete a search operation. Relevant node statistics: Average Relevant cluster statistics: Average, Maximum 
SearchRate 
The total number of search requests per minute for all shards on a
data node. A single call to the Relevant node statistics: Average Relevant cluster statistics: Average, Maximum, Sum 
SysMemoryUtilization 
The percentage of the instance's memory that is in use. High
values for this metric are normal and usually do not represent a
problem with your cluster. For a better indicator of potential
performance and stability issues, see the
Relevant node statistics: Minimum, Maximum, Average Relevant cluster statistics: Minimum, Maximum, Average 
JVMGCYoungCollectionCount 
The number of times that "young generation" garbage collection has run. A large, evergrowing number of runs is a normal part of cluster operations. Relevant node statistics: Maximum Relevant cluster statistics: Sum, Maximum, Average 
JVMGCYoungCollectionTime 
The amount of time, in milliseconds, that the cluster has spent performing "young generation" garbage collection. Relevant node statistics: Maximum Relevant cluster statistics: Sum, Maximum, Average 
JVMGCOldCollectionCount 
The number of times that "old generation" garbage collection has run. In a cluster with sufficient resources, this number should remain small and grow infrequently. Relevant node statistics: Maximum Relevant cluster statistics: Sum, Maximum, Average 
JVMGCOldCollectionTime 
The amount of time, in milliseconds, that the cluster has spent performing "old generation" garbage collection. Relevant node statistics: Maximum Relevant cluster statistics: Sum, Maximum, Average 
ThreadpoolForce_mergeQueue 
The number of queued tasks in the force merge thread pool. If the queue size is consistently high, consider scaling your cluster. Relevant node statistics: Maximum Relevant cluster statistics: Sum, Maximum, Average 
ThreadpoolForce_mergeRejected 
The number of rejected tasks in the force merge thread pool. If this number continually grows, consider scaling your cluster. Relevant node statistics: Maximum Relevant cluster statistics: Sum 
ThreadpoolForce_mergeThreads 
The size of the force merge thread pool. Relevant node statistics: Maximum Relevant cluster statistics: Average, Sum 
ThreadpoolIndexQueue 
The number of queued tasks in the index thread pool. If the queue size is consistently high, consider scaling your cluster. The maximum index queue size is 200. Relevant node statistics: Maximum Relevant cluster statistics: Sum, Maximum, Average 
ThreadpoolIndexRejected 
The number of rejected tasks in the index thread pool. If this number continually grows, consider scaling your cluster. Relevant node statistics: Maximum Relevant cluster statistics: Sum 
ThreadpoolIndexThreads 
The size of the index thread pool. Relevant node statistics: Maximum Relevant cluster statistics: Average, Sum 
ThreadpoolSearchQueue 
The number of queued tasks in the search thread pool. If the queue size is consistently high, consider scaling your cluster. The maximum search queue size is 1,000. Relevant node statistics: Maximum Relevant cluster statistics: Sum, Maximum, Average 
ThreadpoolSearchRejected 
The number of rejected tasks in the search thread pool. If this number continually grows, consider scaling your cluster. Relevant node statistics: Maximum Relevant cluster statistics: Sum 
ThreadpoolSearchThreads 
The size of the search thread pool. Relevant node statistics: Maximum Relevant cluster statistics: Average, Sum 
ThreadpoolBulkQueue 
The number of queued tasks in the bulk thread pool. If the queue size is consistently high, consider scaling your cluster. Relevant node statistics: Maximum Relevant cluster statistics: Sum, Maximum, Average 
ThreadpoolBulkRejected 
The number of rejected tasks in the bulk thread pool. If this number continually grows, consider scaling your cluster. Relevant node statistics: Maximum Relevant cluster statistics: Sum 
ThreadpoolBulkThreads 
The size of the bulk thread pool. Relevant node statistics: Maximum Relevant cluster statistics: Average, Sum 
ThreadpoolWriteThreads 
The size of the write thread pool. Relevant node statistics: Maximum Relevant cluster statistics: Average, Sum 
ThreadpoolWriteRejected 
The number of rejected tasks in the write thread pool. Relevant node statistics: Maximum Relevant cluster statistics: Average, Sum 
ThreadpoolWriteQueue 
The number of queued tasks in the write thread pool. Relevant node statistics: Maximum Relevant cluster statistics: Average, Sum 
UltraWarm Metrics
Amazon Elasticsearch Service provides the following metrics for UltraWarm nodes.
Metric  Description 

WarmCPUUtilization 
The percentage of CPU usage for UltraWarm nodes in the cluster. Maximum shows the node with the highest CPU usage. Average represents all UltraWarm nodes in the cluster. This metric is also available for individual UltraWarm nodes. Relevant statistics: Maximum, Average 
WarmFreeStorageSpace 
The amount of free warm storage space in MiB. Because UltraWarm
uses Amazon S3 rather than attached disks, Relevant statistics: Sum 
WarmJVMMemoryPressure 
The maximum percentage of the Java heap used for the UltraWarm nodes. Relevant statistics: Maximum 
WarmSearchableDocuments 
The total number of searchable documents across all warm indices in the cluster. You must leave the period at one minute to get an accurate value. Relevant statistics: Sum 

The average time, in milliseconds, that it takes a shard on an UltraWarm node to complete a search operation. Relevant node statistics: Average Relevant cluster statistics: Average, Maximum 

The total number of search requests per minute for all shards on
an UltraWarm node. A single call to the Relevant node statistics: Average Relevant cluster statistics: Average, Maximum, Sum 
WarmStorageSpaceUtilization 
The total amount of warm storage space that the cluster is using. The Amazon ES console displays this value in GiB. The Amazon CloudWatch console displays it in MiB. Relevant statistics: Maximum 

The total amount of hot storage space that the cluster is using. Relevant statistics: Maximum 
WarmSysMemoryUtilization 
The percentage of the warm node's memory that is in use. Relevant statistics: Maximum 

The number of indices currently waiting to migrate from hot to warm storage. Relevant statistics: Maximum 

The number of indices currently waiting to migrate from warm to hot storage. Relevant statistics: Maximum 

The total number of failed hot to warm migrations. Relevant statistics: Sum 

The average latency of the force merge stage of the migration
process. If this stage consistently takes too long, consider
increasing
Relevant statistics: Average 

The average latency of the snapshot stage of the migration process. If this stage consistently takes too long, ensure that your shards are appropriately sized and distributed throughout the cluster. Relevant statistics: Average 

The average latency of successful hot to warm migrations, not including time spent in the queue. This value is the sum of the amount of time it takes to complete the force merge, snapshot, and shard relocation stages of the migration process. Relevant statistics: Average 

The total number of successful hot to warm migrations. Relevant statistics: Sum 

The average latency of successful hot to warm migrations, including time spent in the queue. Relevant statistics: Average 
Alerting Metrics
Amazon Elasticsearch Service provides the following metrics for the alerting feature.
Metric  Description 

AlertingDegraded 
A value of 1 means that either the alerting index is red or one or more nodes is not on schedule. A value of 0 indicates normal behavior. Relevant statistics: Maximum 
AlertingIndexExists 
A value of 1 means the Relevant statistics: Maximum 
AlertingIndexStatus.green 
The health of the index. A value of 1 means green. A value of 0 means that the index either doesn't exist or isn't green. Relevant statistics: Maximum 
AlertingIndexStatus.red 
The health of the index. A value of 1 means red. A value of 0 means that the index either doesn't exist or isn't red. Relevant statistics: Maximum 
AlertingIndexStatus.yellow 
The health of the index. A value of 1 means yellow. A value of 0 means that the index either doesn't exist or isn't yellow. Relevant statistics: Maximum 
AlertingNodesNotOnSchedule 
A value of 1 means some jobs are not running on schedule. A value
of 0 means that all alerting jobs are running on schedule (or that
no alerting jobs exist). Check the Amazon ES console or make a
Relevant statistics: Maximum 
AlertingNodesOnSchedule 
A value of 1 means that all alerting jobs are running on schedule (or that no alerting jobs exist). A value of 0 means some jobs are not running on schedule. Relevant statistics: Maximum 
AlertingScheduledJobEnabled 
A value of 1 means that the
Relevant statistics: Maximum 
Anomaly Detection Metrics
Amazon Elasticsearch Service provides the following metrics for the anomaly detection feature.
Metric  Description 

AnomalyDetectionPluginUnhealthy 
A value of 1 means that the anomaly detection plugin is not functioning properly, either because of a high number of failures or because one of the indices that it uses is red. A value of 0 indicates the plugin is working as expected. Relevant statistics: Maximum 
AnomalyDetectionRequestCount 
The number of requests to detect anomalies. Relevant statistics: Sum 
AnomalyDetectionFailureCount 
The number of failed requests to detect anomalies. Relevant statistics: Sum 
AnomalyResultsIndexStatusIndexExists 
A value of 1 means the index that the
Relevant statistics: Maximum 
AnomalyResultsIndexStatus.red 
A value of 1 means the index that the
Relevant statistics: Maximum 
AnomalyDetectorsIndexStatusIndexExists 
A value of 1 means that the
Relevant statistics: Maximum 
AnomalyDetectorsIndexStatus.red 
A value of 1 means that the
Relevant statistics: Maximum 
ModelsCheckpointIndexStatusIndexExists 
A value of 1 means that the
Relevant statistics: Maximum 
ModelsCheckpointIndexStatus.red 
A value of 1 means that the
Relevant statistics: Maximum 
SQL Metrics
Amazon Elasticsearch Service provides the following metrics for SQL support.
Metric  Description 

SQLFailedRequestCountByCusErr 
The number of requests to the Relevant statistics: Sum 
SQLFailedRequestCountBySysErr 
The number of requests to the Relevant statistics: Sum 
SQLRequestCount 
The number of requests to the Relevant statistics: Sum 
SQLDefaultCursorRequestCount 
Similar to Relevant statistics: Sum 
SQLUnhealthy 
A value of 1 indicates that, in response to certain requests, the SQL plugin is returning 5xx response codes or passing invalid query DSL to Elasticsearch. Other requests should continue to succeed. A value of 0 indicates no recent failures. If you see a sustained value of 1, troubleshoot the requests your clients are making to the plugin. Relevant statistics: Maximum 
KNN Metrics
Amazon Elasticsearch Service includes metrics for KNN.
Metric  Description 

KNNCacheCapacityReached 
Pernode metric for whether cache capacity has been reached. This metric is only relevant to approximate KNN search. Relevant statistics: Maximum 
KNNCircuitBreakerTriggered 
Percluster metric for whether the circuit breaker is triggered.
If any nodes return a value of 1 for
Relevant statistics: Maximum 
KNNEvictionCount 
Pernode metric for the number of graphs that have been evicted from the cache due to memory constraints or idle time. Explicit evictions that occur because of index deletion are not counted. This metric is only relevant to approximate KNN search. Relevant statistics: Sum 
KNNGraphIndexErrors 
Pernode metric for the number of requests to add the
Relevant statistics: Sum 
KNNGraphIndexRequests 
Pernode metric for the number of requests to add the
Relevant statistics: Sum 
KNNGraphMemoryUsage 
Pernode metric for the current cache size (total size of all graphs in memory) in kilobytes. This metric is only relevant to approximate KNN search. Relevant statistics: Average 
KNNGraphQueryErrors 
Pernode metric for the number of graph queries that produced an error. Relevant statistics: Sum 
KNNGraphQueryRequests 
Pernode metric for the number of graph queries. Relevant statistics: Sum 
KNNHitCount 
Pernode metric for the number of cache hits. A cache hit occurs when a user queries a graph that is already loaded into memory. This metric is only relevant to approximate KNN search. Relevant statistics: Sum 
KNNLoadExceptionCount 
Pernode metric for the number of times an exception occurred while trying to load a graph into the cache. This metric is only relevant to approximate KNN search. Relevant statistics: Sum 
KNNLoadSuccessCount 
Pernode metric for the number of times the plugin successfully loaded a graph into the cache. This metric is only relevant to approximate KNN search. Relevant statistics: Sum 
KNNMissCount 
Pernode metric for the number of cache misses. A cache miss occurs when a user queries a graph that is not yet loaded into memory. This metric is only relevant to approximate KNN search. Relevant statistics: Sum 
KNNQueryRequests 
Pernode metric for the number of query requests the KNN plugin received. Relevant statistics: Sum 
KNNScriptCompilationErrors 
Pernode metric for the number of errors during script compilation. This statistic is only relevant to KNN score script search. Relevant statistics: Sum 
KNNScriptCompilations 
Pernode metric for the number of times the KNN script has been compiled. This value should usually be 1 or 0, but if the cache containing the compiled scripts is filled, the KNN script might be recompiled. This statistic is only relevant to KNN score script search. Relevant statistics: Sum 
KNNScriptQueryErrors 
Pernode metric for the number of errors during script queries. This statistic is only relevant to KNN score script search. Relevant statistics: Sum 
KNNScriptQueryRequests 
Pernode metric for the total number of script queries. This statistic is only relevant to KNN score script search. Relevant statistics: Sum 
KNNTotalLoadTime 
The time in nanoseconds that KNN has taken to load graphs into the cache. This metric is only relevant to approximate KNN search. Relevant statistics: Sum 
CrossCluster Search Metrics
Amazon Elasticsearch Service provides the following metrics for Crosscluster search.
Source domain metrics
Metric  Dimension  Description 

CrossClusterOutboundConnections 

Number of connected nodes. If your response includes one or more skipped domains, use this metric to trace any unhealthy connections. If this number drops to 0, then the connection is unhealthy. 
CrossClusterOutboundRequests 

Number of search requests sent to the destination domain. Use to check if the load of crosscluster search requests are overwhelming your domain, correlate any spike in this metric with any JVM/CPU spike. 
Destination domain metric
Metric  Dimension  Description 

CrossClusterInboundRequests 

Number of incoming connection requests received from the source domain. 
Add a CloudWatch alarm in the event that you lose a connection unexpectedly. For steps to create an alarm, see Create a CloudWatch Alarm Based on a Static Threshold.
Learning to Rank Metrics
Amazon Elasticsearch Service provides the following metrics for Learning to Rank.
Metric  Description 

LTRRequestTotalCount 
Total count of ranking requests. 
LTRRequestErrorCount 
Total count of unsuccessful requests. 
LTRStoreIndexIsRed 
Tracks if one of the indices needed to run the plugin is red. 
LTRMemoryUsage 
Total memory used by the plugin. 