The database uses PSQL and JDBC to connect remotely and disconnect automatically from time to time

Environmental Science

system platform ：Linux x86-64 Red Hat Enterprise Linux 7,Linux x86-64 Red Hat Enterprise Linux 6, Galaxy Unicorn U system （CPU Feiteng ）4

edition ：4.5

symptoms

Hangao database is in use psql Tools and jdbc When making a remote connection , Report an error after a certain time - Fatal error ：terminating connection due to client no input timeout.

Check safety parameters ,hg_clientnoinput = 0;

Question why

operating system TCP The relevant parameters are set incorrectly , The database follows the operating system configuration , Lead to TCP The survival mechanism has not taken effect .

Solution

After the database is configured as follows , Problem solving ：

# The default values of the following parameters are 0, Indicates the configuration of the continuation server .

tcp_keepalives_idle = '60'

tcp_keepalives_interval = '20'

tcp_keepalives_count = '10'

Parameter description ：

• ​ tcp_keepalives_idle​ (​ integer​) Specify that the operating system sends a TCP keepalive The total amount of time without network activity after the message . If you specify a value without a unit , In seconds . value 0( The default value is ) Indicates that the default value of the operating system is selected . Specify how many seconds to pass after inactivity TCP Send a keepalive news . 0 Value means the default value is used . This parameter is only supported ​ TCP_KEEPIDLE​  Or equivalent socket option system or Windows You can only use . On other systems , It must be zero . Through Unix In the session of domain socket connection , This parameter is ignored and always read as zero .
• ​ tcp_keepalives_interval​ (​ integer​)
  Specify the receipt that is not confirmed by the client TCP keepalive The length of time the message should be retransmitted . If you specify a value without a unit , In seconds . value 0( The default value is ) Indicates that the default value of the operating system is selected . This parameter is only supported ​ TCP_KEEPINTVL​ Or equivalent socket option system or Windows You can only use . On other systems , It has to be zero . Through Unix In the session of domain socket connection , This parameter is ignored and always read as zero .
• ​ tcp_keepalives_count​ (​ integer​) Specifies that the connection from the server to the client can be lost before it is considered disconnected TCP keepalive The number of messages . value 0( The default value is ) Indicates that the default value of the operating system is selected . This parameter is only supported ​ TCP_KEEPCNT​  Or equivalent socket option . On other systems , It has to be zero . Through Unix In the session of domain socket connection , This parameter is ignored and always read as zero .
• ​ tcp_user_timeout​ (​ integer​) Specifies that the transmitted data is in TCP The amount of time that a connection can remain in an unconfirmed state before it is forcibly closed . If you specify a value without a unit , In milliseconds . value 0( The default value is ) Indicates that the default value of the operating system is selected . This parameter is only supported ​ TCP_USER_TIMEOUT​  Is supported on the system ; On other systems , It must be zero . Through Unix-domain In a socket connected session , This parameter will be ignored and always read as zero .

Methods of configuration information related to the server ：

[[email protected] ~]# cat /proc/sys/net/ipv4/tcp_keepalive_time
[[email protected] ~]# cat /proc/sys/net/ipv4/tcp_keepalive_intvl

[[email protected] ~]# cat /proc/sys/net/ipv4/tcp_keepalive_probes