- Logstash Reference: other versions:
- Logstash Introduction
- Getting Started with Logstash
- How Logstash Works
- Setting Up and Running Logstash
- Logstash Directory Layout
- Logstash Configuration Files
- logstash.yml
- Secrets keystore for secure settings
- Running Logstash from the Command Line
- Running Logstash as a Service on Debian or RPM
- Running Logstash on Docker
- Configuring Logstash for Docker
- Running Logstash on Kubernetes
- Running Logstash on Windows
- Logging
- Shutting Down Logstash
- Upgrading Logstash
- Creating a Logstash pipeline
- Secure your connection
- Advanced Logstash Configurations
- Logstash-to-Logstash communication
- Managing Logstash
- Using Logstash with Elastic Integrations
- Working with Logstash Modules
- Working with Filebeat Modules
- Working with Winlogbeat Modules
- Queues and data resiliency
- Transforming Data
- Deploying and Scaling Logstash
- Managing GeoIP Databases
- Performance tuning
- Monitoring Logstash with Elastic Agent
- Monitoring Logstash (legacy)
- Monitoring Logstash with APIs
- Working with plugins
- Integration plugins
- Input plugins
- azure_event_hubs
- beats
- cloudwatch
- couchdb_changes
- dead_letter_queue
- elastic_agent
- elastic_serverless_forwarder
- elasticsearch
- exec
- file
- ganglia
- gelf
- generator
- github
- google_cloud_storage
- google_pubsub
- graphite
- heartbeat
- http
- http_poller
- imap
- irc
- java_generator
- java_stdin
- jdbc
- jms
- jmx
- kafka
- kinesis
- logstash
- log4j
- lumberjack
- meetup
- pipe
- puppet_facter
- rabbitmq
- redis
- relp
- rss
- s3
- s3-sns-sqs
- salesforce
- snmp
- snmptrap
- sqlite
- sqs
- stdin
- stomp
- syslog
- tcp
- udp
- unix
- varnishlog
- websocket
- wmi
- xmpp
- Output plugins
- boundary
- circonus
- cloudwatch
- csv
- datadog
- datadog_metrics
- dynatrace
- elastic_app_search
- elastic_workplace_search
- elasticsearch
- exec
- file
- ganglia
- gelf
- google_bigquery
- google_cloud_storage
- google_pubsub
- graphite
- graphtastic
- http
- influxdb
- irc
- java_stdout
- juggernaut
- kafka
- librato
- logstash
- loggly
- lumberjack
- metriccatcher
- mongodb
- nagios
- nagios_nsca
- opentsdb
- pagerduty
- pipe
- rabbitmq
- redis
- redmine
- riak
- riemann
- s3
- sink
- sns
- solr_http
- sqs
- statsd
- stdout
- stomp
- syslog
- tcp
- timber
- udp
- webhdfs
- websocket
- xmpp
- zabbix
- Filter plugins
- age
- aggregate
- alter
- bytes
- cidr
- cipher
- clone
- csv
- date
- de_dot
- dissect
- dns
- drop
- elapsed
- elastic_integration
- elasticsearch
- environment
- extractnumbers
- fingerprint
- geoip
- grok
- http
- i18n
- java_uuid
- jdbc_static
- jdbc_streaming
- json
- json_encode
- kv
- memcached
- metricize
- metrics
- mutate
- prune
- range
- ruby
- sleep
- split
- syslog_pri
- threats_classifier
- throttle
- tld
- translate
- truncate
- urldecode
- useragent
- uuid
- wurfl_device_detection
- xml
- Codec plugins
- Tips and best practices
- Troubleshooting
- Contributing to Logstash
- How to write a Logstash input plugin
- How to write a Logstash codec plugin
- How to write a Logstash filter plugin
- How to write a Logstash output plugin
- Logstash Plugins Community Maintainer Guide
- Document your plugin
- Publish your plugin to RubyGems.org
- List your plugin
- Contributing a patch to a Logstash plugin
- Extending Logstash core
- Contributing a Java Plugin
- Breaking changes
- Release Notes
- Logstash 8.17.1 Release Notes
- Logstash 8.17.0 Release Notes
- Logstash 8.16.2 Release Notes
- Logstash 8.16.1 Release Notes
- Logstash 8.16.0 Release Notes
- Logstash 8.15.5 Release Notes
- Logstash 8.15.4 Release Notes
- Logstash 8.15.3 Release Notes
- Logstash 8.15.2 Release Notes
- Logstash 8.15.1 Release Notes
- Logstash 8.15.0 Release Notes
- Logstash 8.14.3 Release Notes
- Logstash 8.14.2 Release Notes
- Logstash 8.14.1 Release Notes
- Logstash 8.14.0 Release Notes
- Logstash 8.13.4 Release Notes
- Logstash 8.13.3 Release Notes
- Logstash 8.13.2 Release Notes
- Logstash 8.13.1 Release Notes
- Logstash 8.13.0 Release Notes
- Logstash 8.12.2 Release Notes
- Logstash 8.12.1 Release Notes
- Logstash 8.12.0 Release Notes
- Logstash 8.11.4 Release Notes
- Logstash 8.11.3 Release Notes
- Logstash 8.11.2 Release Notes
- Logstash 8.11.1 Release Notes
- Logstash 8.11.0 Release Notes
- Logstash 8.10.4 Release Notes
- Logstash 8.10.3 Release Notes
- Logstash 8.10.2 Release Notes
- Logstash 8.10.1 Release Notes
- Logstash 8.10.0 Release Notes
- Logstash 8.9.2 Release Notes
- Logstash 8.9.1 Release Notes
- Logstash 8.9.0 Release Notes
- Logstash 8.8.2 Release Notes
- Logstash 8.8.1 Release Notes
- Logstash 8.8.0 Release Notes
- Logstash 8.7.1 Release Notes
- Logstash 8.7.0 Release Notes
- Logstash 8.6.2 Release Notes
- Logstash 8.6.1 Release Notes
- Logstash 8.6.0 Release Notes
- Logstash 8.5.3 Release Notes
- Logstash 8.5.2 Release Notes
- Logstash 8.5.1 Release Notes
- Logstash 8.5.0 Release Notes
- Logstash 8.4.2 Release Notes
- Logstash 8.4.1 Release Notes
- Logstash 8.4.0 Release Notes
- Logstash 8.3.3 Release Notes
- Logstash 8.3.2 Release Notes
- Logstash 8.3.1 Release Notes
- Logstash 8.3.0 Release Notes
- Logstash 8.2.3 Release Notes
- Logstash 8.2.2 Release Notes
- Logstash 8.2.1 Release Notes
- Logstash 8.2.0 Release Notes
- Logstash 8.1.3 Release Notes
- Logstash 8.1.2 Release Notes
- Logstash 8.1.1 Release Notes
- Logstash 8.1.0 Release Notes
- Logstash 8.0.1 Release Notes
- Logstash 8.0.0 Release Notes
- Logstash 8.0.0-rc2 Release Notes
- Logstash 8.0.0-rc1 Release Notes
- Logstash 8.0.0-beta1 Release Notes
- Logstash 8.0.0-alpha2 Release Notes
- Logstash 8.0.0-alpha1 Release Notes
Memory queue
editMemory queue
editBy default, Logstash uses in-memory bounded queues between pipeline stages (inputs → pipeline workers) to buffer events. If Logstash experiences a temporary machine failure, the contents of the memory queue will be lost. Temporary machine failures are scenarios where Logstash or its host machine are terminated abnormally, but are capable of being restarted.
Benefits of memory queues
editThe memory queue might be a good choice if you value throughput over data resiliency.
- Easier configuration
- Easier management and administration
- Faster throughput
Limitations of memory queues
edit- Can lose data in abnormal termination
- Don’t do well handling sudden bursts of data, where extra capacity in needed for Logstash to catch up
Consider using persistent queues to avoid these limitations.
Memory queue size
editMemory queue size is not configured directly. Instead, it depends on how you have Logstash tuned.
Its upper bound is defined by pipeline.workers
(default: number of CPUs) times the pipeline.batch.size
(default: 125) events.
This value, called the "inflight count," determines maximum number of events that can be held in each memory queue.
Doubling the number of workers OR doubling the batch size will effectively double the memory queue’s capacity (and memory usage). Doubling both will quadruple the capacity (and usage).
Each pipeline has its own queue.
See Tuning and profiling logstash pipeline performance for more info on the effects of adjusting pipeline.batch.size
and pipeline.workers
.
If you need to absorb bursts of traffic, consider using persistent queues instead. Persistent queues are bound to allocated capacity on disk.
Settings that affect queue size
editThese values can be configured in logstash.yml
and pipelines.yml
.
- pipeline.batch.size
- Number events to retrieve from inputs before sending to filters+workers The default is 125.
- pipelines.workers
- Number of workers that will, in parallel, execute the filters+outputs stage of the pipeline. This value defaults to the number of the host’s CPU cores.
Back pressure
editWhen the queue is full, Logstash puts back pressure on the inputs to stall data flowing into Logstash. This mechanism helps Logstash control the rate of data flow at the input stage without overwhelming outputs like Elasticsearch.
Each input handles back pressure independently.
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