Here's a list of candidate parameters in gtm.conf and long option for GTM, GTM-Standby and GTM-Proxy.
| Option | Description | GTM | GTM-Standby | GTM-Proxy |
|---|---|---|---|---|
| my_nodename | Node Name | my_nodename(main.c) | my_nodename(main.c) | TDB(proxy_main.c) |
| my_host | Own host to listen | ListenAddresses(main.c) | ListenAddresses(main.c) | ListenAddresses(proxy_main.c) |
| my_port | Own port to listen | GTMPortNumber(main.c) | GTMPortNumber(main.c) | GTMProxyPortNumber(proxy_main.c) |
| destination_host | Host to connect | No | GTM_ActiveAddress(standby_utils.c) | GTMServerHost(proxy_main.c) |
| destination_port | Port to connect | No | GTM_ActivePort(standby_utils.c) | GTMServerPortNumber(proxy_main.c) |
| log_file | Log file name | GTMLogFile(main.c) | GTMLogFile(main.c) | GTMLogFile(proxy_main.c) |
| log_min_message | Message to log | Yes(elog.c?) | Yes(elog.c?) | Yes(elog.c?) |
| initial_gxid | GXID value to begin | ? | No | No |
| startup | GTM ACT or SBY | Yes(main.c?) | Yes(main.c?) | No |
| worker_thread | Worker Threads for GTM-Proxy | No | No | GTMProxyWorkerThreads(proxy_main.c) |
| err_reporter | Command to report error to outside | Yes | Yes | Yes |
| status_reader | Command to collect cluster status | Yes | Yes | Yes |
| err_wait_opt | If wait for reconnect at failure | No | No | Yes |
| err_wait_interval | How long to wait (in sec) | No | No | Yes |
| err_wait_count | How many times to wait | No | No | Yes |
| keepalives_idle | See tcp_keepalive_time | Yes | Yes | Yes |
| keepalives_interval | See tcp_keepalive_intvl | Yes | Yes | Yes |
| keepalives_count | See tcp_keepalive_probes | Yes | Yes | yes |
Further description is as follows:
- GTM may be allowed to have destination_host and desitnation_port to specify connection point used at the time of switchover.
- I'm not sure if initial_gxid should appear in gtm.conf because this is needed only at the the first time or when GTM restarts after crash, where restart GXID value is not reliable. I'm thinking to leave this in the command option.
- err_reporter and status_reader is an external command to report any error or to obtain global XC cluster status respectively. It is supposed that they are a part of XCM module. Because they are not called frequently, it would be better not to include XCM libaries in GTM.
- err_wait_opt, err_wait_interval and err_wait_count control the behavior of GTM-Proxy when it detects errors in send/receive data with GTM. This is needed to wait for "reconnect" operation when GTM fails.