Set the SO_KEEPALIVE option on the client TCP socket [CORE2752]

firebird-automations commented 15 years ago

Submitted by: Vladimir Arkhipov (arkinform)

It will be useful for server applications, which connects to remote firebird servers (for example, replication servers)

firebird-automations commented 15 years ago

Commented by: @AlexPeshkoff

Vladimir, SO_KEEPALIVE is used by server sockets to detect dead clients. I suppose you wish to check for dead server in your case. But client (unlike server) always can check, is server alife or not, using any API call (information, for example). Next, when server socket detects dead client, it has absolutely clear idea what to do - release all resources, required for that client. Can you explain what should be done in your example? Stop replication thread? Not sure this is good idea.

firebird-automations commented 15 years ago

Modified by: @AlexPeshkoff

assignee: Alexander Peshkov \[ alexpeshkoff \]

firebird-automations commented 15 years ago

Commented by: Vladimir Arkhipov (arkinform)

Yes, I wish to check for dead server (rather for connection abort). In my case replication thread is freezing for a long time (usually for unlimited time) and I want to detect it. Of course I can "ping" the remote port in separated thread, but connection may be already restored, anyway my exist database connection may be dead. More, I need to free this thread but closing database connection from another thread is not very safe. In addition I have many databases (about 30) and I need database pooling for each thread. And freezing prevent from normal processing of next databases in pool. And in this case SO_KEEPALIVE will be applicable.

firebird-automations commented 15 years ago

Commented by: Vladimir Arkhipov (arkinform)

What about resolution for this issue?

firebird-automations commented 15 years ago

Commented by: @dyemanov

I'm scheduling this ticket for v3.0, as v2.5 is already frozen for changes. BTW, I'm not really convinced this is a bug per se. It more looks like an improvement request.

firebird-automations commented 15 years ago

Modified by: @dyemanov

Fix Version: 3\.0 Alpha 1 \[ 10331 \]

firebird-automations commented 14 years ago

Commented by: @AlexPeshkoff

I'm still not absolutely sure that this will work. Keepalive packets are used to check for presence of the other side of network socket when there is *no* network activity on the socket. When replication request from server to another server is sent, it means presence of activity on the socket, therefore generic IP timeouts should work here.

firebird-automations commented 14 years ago

Commented by: Vladimir Arkhipov (arkinform)

Is it possible to use SO_RCVTIMEO and SO_SNDTIMEO socket options instead of SO_KEEPALIVE ?! But on some platforms these options may be unsupported. BTW, I agree that this issue is improvement, sorry :)

firebird-automations commented 14 years ago

Modified by: @dyemanov

issuetype: Bug \[ 1 \] =\> Improvement \[ 4 \]