Communication Library Parameters

This section describes parameter settings and value ranges for communication libraries.

tcp_keepalives_idle

Parameter description: Specifies the interval for transmitting keepalive signals on an OS that supports the TCP_KEEPIDLE socket option. If no keepalive signal is transmitted, the connection is in idle mode.

This parameter is a USERSET parameter. Set it based on instructions provided in Table GUC Parameters.

NOTICE:

• If the OS does not support TCP_KEEPIDLE, set this parameter to 0.
• The parameter is ignored on an OS where connections are established using the Unix domain socket.
• 0 selects the system default.
• This parameter is not shared between different sessions, which means that this parameter may have different values in different sessions.
• When showing this parameter, it is the parameter value in the current session connection, not the value of the guc copy.

Value range: 0 to 3600. The unit is s.

Default value: 0

tcp_keepalives_interval

Parameter description: Specifies the response time before retransmission on an OS that supports the TCP_KEEPINTVL socket option.

This parameter is a USERSET parameter. Set it based on instructions provided in Table GUC Parameters.

Value range: 0 to 180. The unit is s.

Default value: 0

NOTICE:

• If the OS does not support TCP_KEEPINTVL, set this parameter to 0.
• The parameter is ignored on an OS where connections are established using the Unix domain socket.
• 0 selects the system default.
• This parameter is not shared between different sessions, which means that this parameter may have different values in different sessions.
• When showing this parameter, it is the parameter value in the current session connection, not the value of the guc copy.

tcp_keepalives_count

Parameter description: Specifies the number of keepalive signals that can be waited before the MogDB server is disconnected from the client on an OS that supports the TCP_KEEPCNT socket option.

This parameter is a USERSET parameter. Set it based on instructions provided in Table GUC Parameters.

NOTICE:

• If the OS does not support TCP_KEEPCNT, set this parameter to 0.
• The parameter is ignored on an OS where connections are established using the Unix domain socket.
• 0 selects the system default.
• This parameter is not shared between different sessions, which means that this parameter may have different values in different sessions.
• When showing this parameter, it is the parameter value in the current session connection, not the value of the guc copy.

Value range: 0 to 100. 0 indicates that the connection is immediately broken if MogDB does not receive a keepalived signal from the client.

Default value: 0

comm_proxy_attr

Parameter description: Specifies the parameters related to the communication proxy library.

NOTE:

• This parameter applies only to the centralized ARM standalone system running EulerOS 2.9.
• This function takes effect when the thread pool is enabled, that is, enable_thread_pool is set to on.
• When setting this parameter, you need to set the GUC parameter local_bind_address to the IP address of the NIC of the libos_kni.
• Parameter template: comm_proxy_attr = '{enable_libnet:true, enable_dfx:false, numa_num:4, numa_bind:[[30,31],[62,63],[94,95],[126,127]]}'
• Parameters that need to be configured include:
  • enable_libnet: whether to enable the user-mode protocol. The options are as follows: true and false.
  • enable_dfx: whether to enable the communication proxy library view. The options are as follows: true and false.
  • numa_num: number of NUMA nodes in the system. 2P and 4P servers are supported. The value can be: 4 or 8.
  • numa_bind: core binding parameter of the agent thread. Each numa has two CPUs. There are a total of numa_num groups. The value range is as follows: [0, Number of CPUs - 1].

This parameter is a POSTMASTER parameter. Set it based on instructions provided in Table GUC Parameters.

Value range: a string, consisting of one or more characters

Default value: none