- Download link
- Run
- Run bin/elasticsearch on Unix
- Run bin/elasticsearch.bat on Windows
- Run 'curl -X GET http://localhost:9200/' in command prompt. If you have not setup cURL setup.
- This is the default cluster with name 'elasticsearch'.
- We should do following to improve performance of elasticsearch
- Increase JVM memory.
- Increase number of open file descriptors.
- Increase virtual memory.
- Disable swapping.
Configurations:
- By default the process will be in foreground which can be toggled to background using '-d' and toggled back to foreground using '-f'.
- We can configure using -X and -D parameters while starting the cluster which will override default JAVA_OPTS or ES_JAVA_OPTS configuration.
- Example: 'bin/elasticsearch -Xmx2g -Xms2g -Des.index.store.type=memory --node.name=my-node'
- Xmx stands for maximum memory allocation pool for a Java Virtual Machine (JVM).
- Xms stands for initial memory allocation pool for a Java Virtual Machine (JVM).
- -Xmx1024k - 1024 kilobytes
- -Xmx512m - 512 MB
- -Xmx8g - 8 GB
- ES_HEAP_SIZE helps in setting heap memory that is allocated to elasticsearch java process. It can be set using ES_MIN_MEM and ES_MAX_MEM parameters.
System Configurations:
- file descriptors
- Set maximum file descriptors.
- '_setmaxstdio' for windows by default is 512 and maximum is 2048.
- Recommended is 32k, 64k.
- To view the number of file descriptors for the process use parameter '-Des.max-open-files=true' which will print the number of file descriptors for the process.
- Alternatively user 'curl localhost:9200/_nodes/process?pretty'
- virtual memory
- By default mmap count is low for the operating system it can be improved.
- 'sysctl -w vm.max_map_count=262144' in linux,
- This can be set permanently using '/etc/sysctl.conf' file and updating 'vm.max_map_count=262144'.
- memory settings
- swap
- By default linux swaps out processes which are not used which will result in poor node stability so swapping should be disabled.
- Three options for swap
- Disable swap completely.
- sudo swapoff -a
- Permanent Setting: comment out lines for 'swap' in '/etc/fstab'
- Set vm.swappiness = 0, but still swap under emergency conditions.
- mlockall, this locks address space into RAM which prevents swapping out.
- set 'bootstrap.mlockall : true' in 'config/elasticsearch.yml'.
elasticsearch Settings:
- Configuration files: are found under 'ES_HOME/config'.
- 'elasticsearch.yml' for configuring elasticsearch different modules.
- 'logging.yml' for configuring elasticsearch logging.
- Paths for logs and data (path)
- Usage: path.logs = 'path for logs', path.data = 'path for data'
- Usage in commands: "-Des.path.logs = '/var/log/elasticsearch'"
path: logs: /var/log/elasticsearch data: /var/data/elasticsearch
- Cluster Name (cluster)
- Usage: cluster.name = 'name of your cluster'
- Usage in commands: "-Des.cluster.name = 'name of your cluster'"
cluster: name: <NAME OF YOUR CLUSTER>
- Node Name (node), this is the default node name. By default it will randomly assign a Marvel character name.
- Usage: node.name = 'name of your node'
- Usage in commands: "-Des.node.name = 'name of your node'"
node: name: <NAME OF YOUR NODE>
- By default uses YAML format, can be converted to JSON if necessary where Node Name will be:
{ "node" : { "name" : "NAME OF YOUR NODE" } }
- If an external file is used it can be configured using '-Des.config = /path/to/config/file'.
index settings
- indices created can be memory based or file based. By default it is file based and can be memory based by passing YAML or JSON paramter.
- Usage in commands: "-Des.index.store.type = memory"
logging
- uses log4j and supports yaml/json/properties formats. If multiple files are present it merges all the files.
- Prefix: logging.
- Suffix: .yml, .yaml, .json, .properties
- Folder contains required java packages.
multiple data
- path.data: /mnt/first,/mnt/second
- path.data: ["/mnt/first", "/mnt/second"]
