Hi William, Thanks for looking into it! The timeout also would work very well. I just tried it out and no issues at all.
Regarding the CI problem: I found a way to avoid using signals by using "debug dev delay" + "nbthread 1" for the vtests. Please let me know if that would work in the CI environment. I composed everything into a new patch and added you as the Co-Author. Please let me know if the patch looks good now. Best regards, Alexander -----Original Message----- From: William Lallemand <[email protected]> Sent: Thursday, April 30, 2026 3:49 PM To: Stephan, Alexander <[email protected]> Cc: [email protected] Subject: Re: [PATCH] BUG/MEDIUM: cli: fix master CLI connection slot leak on client disconnect Hello Alexander, On Wed, Apr 29, 2026 at 05:04:20PM +0000, Stephan, Alexander wrote: > The patch works like this: > > 1. In pcli_wait_for_request(), when the response analyzer is active > and the frontend stream connector shows a client disconnect (SC_FL_EOS > or SC_FL_ABRT_DONE on scf), explicitly call > sc_abort(s->scb) to propagate the disconnect to the backend. > 2. In pcli_wait_for_response(), extend the error condition to also > check for SC_FL_ABRT_DONE on scb. This flag is only set by the > explicit sc_abort() above, so normal one-shot CLI tools that close > their TCP connection after receiving a response are not affected. The disconnect should already be propagated to the backend, but if the backend does not respond anymore, we never receive the FIN/ACK so we can't clean correctly. It's suppose to be handled with timeouts in a standard proxy. But we don't have timeouts on the master CLI. Adding a server timeout might be problematic because it would change the behavior on long waiting commands, however adding a timeout server-fin might help closing without waiting for the worker. diff --git a/src/cli.c b/src/cli.c index 3bd7098981..3043ceb8e2 100644 --- a/src/cli.c +++ b/src/cli.c @@ -3834,8 +3834,9 @@ int mworker_cli_create_master_proxy(char **errmsg) mworker_proxy->mode = PR_MODE_CLI; /* default to 10 concurrent connections */ mworker_proxy->maxconn = 10; - /* no timeout */ - mworker_proxy->timeout.client = 0; + mworker_proxy->timeout.client = 0; /* no timeout */ + mworker_proxy->timeout.serverfin = MS_TO_TICKS(1000); /* 1s + timeout in case worker is not responding on shutdown */ + mworker_proxy->conf.file = strdup("MASTER"); mworker_proxy->conf.line = 0; mworker_proxy->accept = frontend_accept; I tested the above change and it seems to fix the issue, could you confirm with your setup? > A regression test is included. > This should be backported to all stable branches. > That kind of test might be problematic in the CI, signals are not really reliable in the CI environment, it might cause flappy results. Regards, -- William Lallemand
0001-BUG-MEDIUM-cli-fix-master-CLI-connection-slot-leak-o.patch
Description: 0001-BUG-MEDIUM-cli-fix-master-CLI-connection-slot-leak-o.patch
