varnishd: add VSC per backend connection closed

Change vbe_close_acct to update counters for the specific backend
as well as the existing global counters. This addition allows a user to
easily pinpoint the problematic backend. As some backends can come and
go (dynamic backends), we should maintain the global counters as is.

Signed-off-by: Asad Sajjad Ahmed <asadsa@varnish-software.com>

Author: asadsa92

bin/varnishd/cache/cache_backend.c

@@ -189,20 +189,25 @@ vbe_connwait_fini(struct connwait *cw)
  */
 
 static void
-vbe_close_acct(const struct pfd *pfd, const stream_close_t reason)
+vbe_close_acct(const struct pfd *pfd, struct VSC_vbe *vsc,
+    const stream_close_t reason)
 {
 
 	if (reason == SC_NULL) {
 		assert(PFD_State(pfd) == PFD_STATE_USED);
 		VSC_C_main->bc_tx_proxy++;
+		vsc->tx_proxy++;
 		return;
 	}
 
 #define SESS_CLOSE(U, l, err, desc)					\
 	if (reason == SC_ ## U) {					\
 		VSC_C_main->bc_ ## l++;					\
-		if (err)						\
+		vsc->l++;					\
+		if (err) {						\
 			VSC_C_main->backend_closed_err++;		\
+			vsc->closed_err++;				\
+		}							\
 		return;							\
 	}
 #include "tbl/sess_close.h"
@@ -222,20 +227,22 @@ vbe_dir_finish(VRT_CTX, VCL_BACKEND d)
 	bo = ctx->bo;
 	CHECK_OBJ_NOTNULL(bo, BUSYOBJ_MAGIC);
 	CAST_OBJ_NOTNULL(bp, d->priv, BACKEND_MAGIC);
+	AN(bp->vsc);
 
 	CHECK_OBJ_NOTNULL(bo->htc, HTTP_CONN_MAGIC);
 	CHECK_OBJ_NOTNULL(bo->htc->doclose, STREAM_CLOSE_MAGIC);
 
 	pfd = bo->htc->priv;
 	bo->htc->priv = NULL;
 	if (bo->htc->doclose != SC_NULL || bp->proxy_header != 0) {
-		vbe_close_acct(pfd, bo->htc->doclose);
+		vbe_close_acct(pfd, bp->vsc, bo->htc->doclose);
 		VSLb(bo->vsl, SLT_BackendClose, "%d %s close %s", *PFD_Fd(pfd),
 		    VRT_BACKEND_string(d), bo->htc->doclose->name);
 		VCP_Close(&pfd);
 		AZ(pfd);
 		Lck_Lock(bp->director->mtx);
 		VSC_C_main->backend_closed++;
+		bp->vsc->closed++;
 	} else {
 		assert (PFD_State(pfd) == PFD_STATE_USED);
 		VSLb(bo->vsl, SLT_BackendClose, "%d %s recycle", *PFD_Fd(pfd),

bin/varnishtest/tests/o00007.vtc

@@ -40,3 +40,11 @@ varnish v1 -expect MAIN.bc_tx_proxy == 0
 varnish v1 -expect VBE.vcl1.default.conn == 0
 varnish v1 -expect VBE.vcl1.default.req == 0
 varnish v1 -expect VBE.vcl1.default.fail == 0
+varnish v1 -expect VBE.vcl1.default.closed == 1
+varnish v1 -expect VBE.vcl1.default.closed_err == 1
+
+varnish v1 -expect VBE.vcl1.default.rx_bad == 0
+varnish v1 -expect VBE.vcl1.default.rem_close == 0
+varnish v1 -expect VBE.vcl1.default.rx_timeout == 0
+varnish v1 -expect VBE.vcl1.default.tx_error == 1
+varnish v1 -expect VBE.vcl1.default.tx_proxy == 0

bin/varnishtest/tests/u00008.vtc

@@ -70,10 +70,12 @@ process p1 -winsz 25 132
 process p1 -expect-text 4 124 "AVG_1000"
 process p1 -expect-text 22 108 "UNSEEN  DIAG"
 
+process p1 -key NPAGE
 process p1 -key NPAGE
 process p1 -expect-text 0 0 "VBE.vcl1.s1.helddown"
 process p1 -screen_dump
 
+process p1 -key PPAGE
 process p1 -key PPAGE
 process p1 -expect-text 0 0 "VBE.vcl1.s1.happy"
 process p1 -screen_dump

lib/libvsc/VSC_vbe.vsc

@@ -104,6 +104,86 @@
 
 	Number of times the max_connections limit was reached
 
+.. varnish_vsc:: closed
+	:type:	counter
+	:level: info
+	:oneliner:	Connection closed
+
+.. varnish_vsc:: closed_err
+	:type:	counter
+	:level: info
+	:oneliner:	Connection closed with error
+
+.. varnish_vsc:: rem_close
+	:type:	counter
+	:level: info
+	:oneliner:	Connection closed by backend
+
+.. varnish_vsc:: req_close
+	:type:	counter
+	:level: info
+	:oneliner:	Connection closure requested by backend
+
+.. varnish_vsc:: req_http10
+	:type:	counter
+	:level: info
+	:oneliner:	Connection closed for proto < HTTP/1.1
+
+.. varnish_vsc:: rx_bad
+	:type:	counter
+	:level: info
+	:oneliner:	Connection closed for received bad response
+
+.. varnish_vsc:: rx_body
+	:type:	counter
+	:level: info
+	:oneliner:	Connection closed for failed receiving request body
+
+.. varnish_vsc:: rx_junk
+	:type:	counter
+	:level: info
+	:oneliner:	Connection closed for received junk data
+
+.. varnish_vsc:: rx_overflow
+	:type:	counter
+	:level: info
+	:oneliner:	Connection closed for receive buffer overflow
+
+.. varnish_vsc:: rx_timeout
+	:type:	counter
+	:level: info
+	:oneliner:	Connection closed for receive timeout
+
+.. varnish_vsc:: tx_proxy
+	:type:	counter
+	:level: info
+	:oneliner:	Connection closed for proxy transaction
+
+.. varnish_vsc:: tx_pipe
+	:type:	counter
+	:level: info
+	:oneliner:	Connection closed for piped transaction
+
+.. varnish_vsc:: tx_error
+	:type:	counter
+	:level: info
+	:oneliner:	Connection closed for error transaction
+
+.. varnish_vsc:: tx_eof
+	:type:	counter
+	:level: info
+	:oneliner:	Connection closed for EOF transmission
+
+.. varnish_vsc:: resp_close
+	:type:	counter
+	:level: info
+	:oneliner:	Connection closed for backend/VCL requested close
+
+.. varnish_vsc:: overload
+	:type:	counter
+	:level: info
+	:oneliner:	Connection closed for out of some resource
+
 ..
 	=== Anything below is actually per VCP entry, but collected per
 	=== backend for simplicity