Mailing List Archive

Author: phk
Date: 2007-01-22 14:24:42 +0100 (Mon, 22 Jan 2007)
New Revision: 1238

Modified:
trunk/varnish-cache/bin/varnishd/cache_backend.c
trunk/varnish-cache/bin/varnishd/cache_vrt.c
Log:
Expend a lock on keeping the backend statistics consistent.
Rename the fields to make more sense



Modified: trunk/varnish-cache/bin/varnishd/cache_backend.c
===================================================================
--- trunk/varnish-cache/bin/varnishd/cache_backend.c 2007-01-22 12:31:52 UTC (rev 1237)
+++ trunk/varnish-cache/bin/varnishd/cache_backend.c 2007-01-22 13:24:42 UTC (rev 1238)
@@ -214,9 +214,12 @@

/* Get a backend connection ------------------------------------------
*
- * First locate the backend shadow, if necessary by creating one.
- * If there are free connections, use the first, otherwise build a
- * new connection.
+ * Try all cached backend connections for this backend, and use the
+ * first one that is looks like it is still connected.
+ * If that fails to get us a connection, create a new one, reusing a
+ * connection from the freelist, if possible.
+ *
+ * This function is slightly complicated by optimizations on vbemtx.
*/

static struct vbe_conn *
@@ -225,20 +228,17 @@
struct vbe_conn *vc, *vc2;
struct pollfd pfd;
struct backend *bp;
+ int reuse = 0;

CHECK_OBJ_NOTNULL(sp, SESS_MAGIC);
bp = sp->backend;
CHECK_OBJ_NOTNULL(bp, BACKEND_MAGIC);
+ vc2 = NULL;
while (1) {
- /*
- * Try all connections on this backend until we find one
- * that works. If that fails, grab a free connection
- * (if any) while we have the lock anyway.
- */
- vc2 = NULL;
LOCK(&vbemtx);
vc = TAILQ_FIRST(&bp->connlist);
if (vc != NULL) {
+ assert(vc->backend == bp);
assert(vc->fd >= 0);
TAILQ_REMOVE(&bp->connlist, vc, list);
} else {
@@ -256,8 +256,10 @@
pfd.fd = vc->fd;
pfd.events = POLLIN;
pfd.revents = 0;
- if (!poll(&pfd, 1, 0))
+ if (!poll(&pfd, 1, 0)) {
+ reuse = 1;
break;
+ }
VBE_ClosedFd(sp->wrk, vc, 0);
}

@@ -266,34 +268,33 @@
vc = vbe_new_conn();
else
vc = vc2;
- AN(vc);
- assert(vc->fd == -1);
- AZ(vc->backend);
+ if (vc != NULL) {
+ assert(vc->fd == -1);
+ AZ(vc->backend);
+ vc->fd = vbe_connect(sp, bp);
+ if (vc->fd < 0) {
+ LOCK(&vbemtx);
+ TAILQ_INSERT_HEAD(&vbe_head, vc, list);
+ VSL_stats->backend_unused++;
+ UNLOCK(&vbemtx);
+ vc = NULL;
+ } else {
+ vc->backend = bp;
+ }
+ }
}
-
- /* If not connected yet, do so */
- if (vc->fd < 0) {
- AZ(vc->backend);
- vc->fd = vbe_connect(sp, bp);
- LOCK(&vbemtx);
- if (vc->fd < 0) {
- vc->backend = NULL;
- TAILQ_INSERT_HEAD(&vbe_head, vc, list);
- VSL_stats->backend_unused++;
- vc = NULL;
- } else {
- vc->backend = bp;
- }
- UNLOCK(&vbemtx);
+ LOCK(&vbemtx);
+ if (vc != NULL ) {
+ VSL_stats->backend_reuse += reuse;
+ VSL_stats->backend_conn++;
} else {
- assert(vc->fd >= 0);
- assert(vc->backend == bp);
+ VSL_stats->backend_fail++;
}
+ UNLOCK(&vbemtx);
if (vc != NULL ) {
+ WSL(sp->wrk, SLT_BackendXID, vc->fd, "%u", sp->xid);
assert(vc->fd >= 0);
- VSL_stats->backend_conn++;
- WSL(sp->wrk, SLT_BackendXID, vc->fd, "%u", sp->xid);
- AN(vc->backend);
+ assert(vc->backend == bp);
}
return (vc);
}
@@ -348,9 +349,9 @@
CHECK_OBJ_NOTNULL(vc, VBE_CONN_MAGIC);
assert(vc->fd >= 0);
AN(vc->backend);
- VSL_stats->backend_recycle++;
WSL(w, SLT_BackendReuse, vc->fd, "%s", vc->backend->vcl_name);
LOCK(&vbemtx);
+ VSL_stats->backend_recycle++;
TAILQ_INSERT_HEAD(&vc->backend->connlist, vc, list);
UNLOCK(&vbemtx);
}

Modified: trunk/varnish-cache/bin/varnishd/cache_vrt.c
===================================================================
--- trunk/varnish-cache/bin/varnishd/cache_vrt.c 2007-01-22 12:31:52 UTC (rev 1237)
+++ trunk/varnish-cache/bin/varnishd/cache_vrt.c 2007-01-22 13:24:42 UTC (rev 1238)
@@ -133,13 +133,14 @@
VRT_free_backends(struct VCL_conf *cp)
{

- (void)cp;
+ (void)cp; /* XXX */
}

void
VRT_fini_backend(struct backend *be)
{
- (void)be;
+
+ (void)be; /* XXX */
}

/*--------------------------------------------------------------------*/