HandlerSocket is a MySQL plugin that implements a NoSQL protocol for MySQL. This allows applications to communicate more directly with MySQL storage engines, without the overhead associated with using SQL. This includes operations such as parsing and optimizing queries, as well as table handling operations (opening, locking, unlocking, closing). As a result, using HandlerSocket can provide much better performance for certain applications that using normal SQL application protocols.

Complete documentation on the HandlerSocket plugin, including installation and configuration options, is located here.

The plugin is disabled by default. To enable it in Percona Server with XtraDB, see below.

Version Specific Information

Other Information

Author/Origin Akira Higuchi, DeNA Co., Ltd.

Enabling the Plugin

Once HandlerSocket has been downloaded and installed on your system, there are two steps required to enable it.

First, add the following lines to the [mysqld] section of your my.cnf file:

loose_handlersocket_port = 9998
  # the port number to bind to for read requests
loose_handlersocket_port_wr = 9999
  # the port number to bind to for write requests
loose_handlersocket_threads = 16
  # the number of worker threads for read requests
loose_handlersocket_threads_wr = 1
  # the number of worker threads for write requests
open_files_limit = 65535
  # to allow handlersocket to accept many concurrent
  # connections, make open_files_limit as large as
  # possible.

Second, log in to mysql as root, and execute the following query:

mysql> install plugin handlersocket soname 'handlersocket.so';

Testing the Plugin installation

If handlersocket.so was successfully installed, it will begin accepting connections on ports 9998 and 9999. Executing a SHOW PROCESSLIST command should show HandlerSocket worker threads:

| Id | User        | Host            | db            | Command | Time | State                                     | Info             |
|  1 | system user | connecting host | NULL          | Connect | NULL | handlersocket: mode=rd, 0 conns, 0 active | NULL             |
|  2 | system user | connecting host | NULL          | Connect | NULL | handlersocket: mode=rd, 0 conns, 0 active | NULL             |
| 16 | system user | connecting host | NULL          | Connect | NULL | handlersocket: mode=rd, 0 conns, 0 active | NULL             |
| 17 | system user | connecting host | handlersocket | Connect | NULL | handlersocket: mode=wr, 0 conns, 0 active | NULL             |

To ensure HandlerSocket is working as expected, you can follow these steps:

Create a new table:

mysql> CREATE TABLE t (
  id int(11) NOT NULL,
  col varchar(20) NOT NULL,

Insert a row with HandlerSocket (fields are separated by tabs):

$ telnet 9999
Connected to
Escape character is '^]'.
P     1       test    t       PRIMARY id      col
0     1
1     +       2       1       test value
0     1

And check in SQL that the row has been written:

mysql> SELECT * FROM t;
| id | col        |
|  1 | test value |

Configuration options

HandlerSocket has many configuration options that are detailed here.

Other Reading

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