varnish plugin: Use a DERIVE type for allocated and free bytes.

Each event is counted, so storing a GAUGE is not the right thing to do.
Thanks to Renaud Chaput for pointing this out.

N.B.: The total amount of allocated memory is tracked by
"bytes-outstanding" for many storage backends.

diff --git a/src/varnish.c b/src/varnish.c
index 6bf2db7..859df21 100644 (file)
--- a/src/varnish.c
+++ b/src/varnish.c
@@ -307,9 +307,9 @@ static void varnish_monitor (const user_config_t *conf, struct varnish_stats *VS
                /* outstanding allocations */
                varnish_submit_gauge (conf->instance,  "sm", "requests", "outstanding", VSL_stats->sm_nobj);
                /* bytes allocated */
-               varnish_submit_gauge (conf->instance,  "sm", "bytes", "allocated",      VSL_stats->sm_balloc);
+               varnish_submit_gauge (conf->instance,  "sm", "total_bytes", "allocated",      VSL_stats->sm_balloc);
                /* bytes free */
-               varnish_submit_gauge (conf->instance,  "sm", "bytes", "free",           VSL_stats->sm_bfree);
+               varnish_submit_gauge (conf->instance,  "sm", "total_bytes", "free",           VSL_stats->sm_bfree);
        }
 
        if (conf->collect_sma)
@@ -321,9 +321,9 @@ static void varnish_monitor (const user_config_t *conf, struct varnish_stats *VS
                /* SMA outstanding bytes */
                varnish_submit_gauge (conf->instance,  "sma", "bytes", "outstanding",    VSL_stats->sma_nbytes);
                /* SMA bytes allocated */
-               varnish_submit_gauge (conf->instance,  "sma", "bytes", "allocated",      VSL_stats->sma_balloc);
+               varnish_submit_gauge (conf->instance,  "sma", "total_bytes", "allocated",      VSL_stats->sma_balloc);
                /* SMA bytes free */
-               varnish_submit_gauge (conf->instance,  "sma", "bytes", "free" ,          VSL_stats->sma_bfree);
+               varnish_submit_gauge (conf->instance,  "sma", "total_bytes", "free" ,          VSL_stats->sma_bfree);
        }
 
        if (conf->collect_sms)
@@ -335,9 +335,9 @@ static void varnish_monitor (const user_config_t *conf, struct varnish_stats *VS
                /* SMS outstanding bytes */
                varnish_submit_gauge (conf->instance,  "sms", "bytes", "outstanding",        VSL_stats->sms_nbytes);
                /* SMS bytes allocated */
-               varnish_submit_gauge (conf->instance,  "sms", "bytes", "allocated",          VSL_stats->sms_balloc);
+               varnish_submit_gauge (conf->instance,  "sms", "total_bytes", "allocated",          VSL_stats->sms_balloc);
                /* SMS bytes freed */
-               varnish_submit_gauge (conf->instance,  "sms", "bytes", "free",               VSL_stats->sms_bfree);
+               varnish_submit_gauge (conf->instance,  "sms", "total_bytes", "free",               VSL_stats->sms_bfree);
        }
 
        if (conf->collect_totals)