| 类型: | integer |
| 默认: | 0 |
| 最低限度: | 0 |
| 最大: | 2147483647 |
| 上下文: | user |
| 重新开始: | false |
指定服务器到客户端的连接被认为中断之前可以丢失的TCP keepalive消息的数量。值0(默认值)表示选择操作系统默认值。 这个参数只有在支持TCP_KEEPCNT或等效套接字选项的系统上才可以使用。在其他系统上，必须为零。在通过 Unix 域套接字连接的会话中，这个参数被忽略并总被读作零。
Windows 不支持该参数，且必须为零。
建议 [EN]
The three tcp_keepalive settings help manage a system which tends to have "undead" connection/query processes. For systems which support them, you can regulate checking that connections are still "live" end-to-end to kill them off. Not needed if you're not having a problem. Should be synchronized with the new TCP keepalive support in libpq on the client side.