From 3a47e5e25c0e5621616b75ab0dd4a56c2f1d0608 Mon Sep 17 00:00:00 2001 From: Christopher Faulet Date: Fri, 25 May 2018 10:42:37 +0200 Subject: [PATCH] BUG/MEDIUM: spoe: Return an error when the wrong ACK is received in sync mode This is required to let a message processing timed out. Because, when it happens, there is no more context attached to the SPOE applet that sent the NOTIFY frame. So when the ACK is received, it is too late. This is the same situation when we receive the wrong ACK. It is invalid in sync mode. Otherwise, the SPOE applet remains in the state "WAITING_SYNC_ACK" until the idle timeout is reached. In such case, the applet is seen as busy and it is unusable. If this happens too often, more and more applets will be created because some others are blocked. If there is a maxconn on the SPOE backend, all processings will be drastically slowdown. Returning an error in such cases, in sync mode, allow us to terminate the SPOE applet. Because it means the agent is unresponsive or too slow. Note this bug exists only if the sync mode is used. This patch must be backported in 1.8. --- src/flt_spoe.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/src/flt_spoe.c b/src/flt_spoe.c index c25630301..7a19a18a7 100644 --- a/src/flt_spoe.c +++ b/src/flt_spoe.c @@ -1030,6 +1030,8 @@ spoe_handle_agentack_frame(struct appctx *appctx, struct spoe_context **ctx, (unsigned int)stream_id, (unsigned int)frame_id); SPOE_APPCTX(appctx)->status_code = SPOE_FRM_ERR_FRAMEID_NOTFOUND; + if (appctx->st0 == SPOE_APPCTX_ST_WAITING_SYNC_ACK) + return -1; return 0; found: