HandlerSocket Configuration Options

The HandlerSocket plugin has the following options.

See also the Full list of MariaDB options, system and status variables.

Add the options to the [mysqld] section of your my.cnf file.

handlersocket_accept_balance

• Description: When set to a value other than zero ('0'), handlersocket will try to balance accepted connections among threads. Default is 0 but if you use persistent connections (for example if you use client-side connection pooling) then a non-zero value is recommended.

• Commandline: --handlersocket-accept-balance="value"

• Scope: Global

• Dynamic: No

• Type: number

• Range: 0 to 10000

• Default Value: 0

handlersocket_address

• Description: Specify the IP address to bind to.

• Commandline: --handlersocket-address="value"

• Scope: Global

• Dynamic: No

• Type: IP Address

• Default Value: Empty, previously 0.0.0.0

handlersocket_backlog

• Description: Specify the listen backlog length.

• Commandline: --handlersocket-backlog="value"

• Scope: Global

• Dynamic: No

• Type: number

• Range: 5 to 1000000

• Default Value: 32768

handlersocket_epoll

• Description: Specify whether to use epoll for I/O multiplexing.

• Commandline: --handlersocket-epoll="value"

• Scope: Global

• Dynamic: No

• Type: number

• Valid values:

  • Min: 0

  • Max: 1

• Default Value: 1

handlersocket_plain_secret

• Description: When set, enables plain-text authentication for the listener for read requests, with the value of the option specifying the secret authentication key.

• Commandline: --handlersocket-plain-secret="value"

• Dynamic: No

• Type: string

• Default Value: Empty

handlersocket_plain_secret_wr

• Description: When set, enables plain-text authentication for the listener for write requests, with the value of the option specifying the secret authentication key.

• Commandline: --handlersocket-plain-secret-wr="value"

• Dynamic: No

• Type: string

• Default Value: Empty

handlersocket_port

• Description: Specify the port to bind to for reads. An empty value disables the listener.

• Commandline: --handlersocket-port="value"

• Scope: Global

• Dynamic: No

• Type: number

• Default Value: Empty, previously 9998

handlersocket_port_wr

• Description: Specify the port to bind to for writes. An empty value disables the listener.

• Commandline: --handlersocket-port-wr="value"

• Scope: Global

• Dynamic: No

• Type: number

• Default Value: Empty, previously 9999

handlersocket_rcvbuf

• Description: Specify the maximum socket receive buffer (in bytes). If '0' then the system default is used.

• Commandline: --handlersocket-rcvbuf="value"

• Scope: Global

• Dynamic: No

• Type: number

• Range: 0 to 1677216

• Default Value: 0

handlersocket_readsize

• Description: Specify the minimum length of the request buffer. Larger values consume available memory but can make handlersocket faster for large requests.

• Commandline: --handlersocket-readsize="value"

• Scope: Global

• Dynamic: No

• Type: number

• Range: 0 to 1677216

• Default Value: 0 (possibly 4096)

handlersocket_sndbuf

• Description: Specify the maximum socket send buffer (in bytes). If '0' then the system default is used.

• Commandline: --handlersocket-sndbuf="value"

• Scope: Global

• Dynamic: No

• Type: number

• Range: 0 to 1677216

• Default Value: 0

handlersocket_threads

• Description: Specify the number of worker threads for reads. Recommended value = ((

CPU cores) * 2).

• Commandline: --handlersocket-threads="value"

• Scope: Global

• Dynamic: No

• Type: number

• Range: 1 to 3000

• Default Value: 16

handlersocket_threads_wr

• Description: Specify the number of worker threads for writes. Recommended value = 1.

• Commandline: --handlersocket-threads-wr="value"

• Scope: Global

• Dynamic: No

• Type: number

• Range: 1 to 3000

• Default Value: 1

handlersocket_timeout

• Description: Specify the socket timeout in seconds.

• Commandline: --handlersocket-timeout="value"

• Scope: Global

• Dynamic: No

• Type: number

• Range: 30 to 3600

• Default Value: 300

handlersocket_verbose

• Description: Specify the logging verbosity.

• Commandline: --handlersocket-verbose="value"

• Scope: Global

• Dynamic: No

• Type: number

• Valid values:

  • Min: 0

  • Max: 10000

• Default Value: 10

handlersocket_wrlock_timeout

• Description: The write lock timeout in seconds. When acting on write requests, handlersocket locks an advisory lock named 'handlersocket_wr' and this option sets the timeout for it.

• Commandline: --handlersocket-wrlock-timeout="value"

• Scope: Global

• Dynamic: No

• Type: number

• Range: 0 to `3600```

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