Jdbc & Mysql timeout analysis

Due to the structure of TPC/IP, there is no way for socket to detect network errors, so the application cannot detect if the connection to the database has been dropped.If the socket timeout is not set, the application will wait for the database to return the result.This article will summarize the timeout parameters and descriptions of Jdbc and MySQL.

Jdbc Connection

Jdbc timeout

Transaction Timeout

Transaction timeout parameter.The time for executing data submission is limited, and an exception will be thrown if the timeout value exceeds the set value.

Statement Timeout

Used to limit the execution time of the statement query.Set by calling JDBC's java.sql.Statement.setQueryTimeout(in timeout) API

connectTimeout

Configure the connection timeout period.Configure by Socket.connect(SocketAddress endpoint, int timeout) method

If the time to establish a connection with the server (here) request exceeds connectTimeout, it will throw ConnectionTimeOutException

socketTimeout

Configure the Socket timeout.Set by Socket.setSoTimeout(int timeout)

If the connection to the server is successful, the data transfer starts.If the server takes too long to process data and exceeds socketTimeout, it will throw SocketTimeOutExceptin, that is, the server response timed out

Mysql timeout

parameter	Description	Features
connect_timeout	Connection response timeout	If the server fails to connect successfully within this time, it will return a connection failure.
wait_timeout	Connection idle timeout	The time to wait for a connection without interaction with the server until it is forcibly closed by the server.It can be considered as the idle time of the server-side connection. If the idle time exceeds this time, it will be automatically closed.
interactive_timeout	Connection idle timeout	The time to wait for a connection without interaction with the server until it is forcibly closed by the server.
net_read_timeout	Data read timeout	The number of seconds to wait to get data from a connection before terminating the read; net_read_timeout controls when to time out when the service is reading data from the client.That is, the client performs data reading, and automatically disconnects after waiting for how many seconds before the execution is successful.
net_write_timeout	Database write timeout	Similar to net_read_timeout, how many seconds to wait to write the block to the connection before terminating the write; when the service is writing data to the client, net_write_timeout controls when it times out.
slave-net-timeout	Delay sync from library	When the slave thinks there is a problem with the connection to the master, it waits for N seconds, then disconnects and reconnects to the master

interactive_timeout and wait_timeout have the same meaning, but there are essential differences in the objects used.Interactive_timeout is for interactive connections (such as connecting to the database through the mysql client), and wait_timeout is for non-interactive connections (such as using PDO to connect to the database in PHP, of course, you can set the CLIENT_INTERACTIVE option to change).The so-called interactive connection, that is, the CLIENT_INTERACTIVE option is used in the mysql_real_connect() function.

• slave-net-timeout works on slave libraries during master-slave synchronization;
• connect_timeout: works during the connection acquisition phase;
• interactive_timeout and wait_timeout: work during the idle phase of the connection;
• net_read_timeout and net_write_timeout: It works when the connection is executed.

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References:

1. Can you understand the difference between connectTimeout and socketTimeout?
2. JDBC does not set the socket timeout, causing the application's thread pool to block
3. Hikari
4. Database related exception analysis
5. Jdbc timeout