[master] 75aa1a805 cache_ban: Add obj.last_hit
Nils Goroll
nils.goroll at uplex.de
Fri Mar 21 14:05:11 UTC 2025
commit 75aa1a8056c56d9b2c7350bf4e2be44b0a4115e4
Author: Nils Goroll <nils.goroll at uplex.de>
Date: Tue Feb 25 17:13:25 2025 +0100
cache_ban: Add obj.last_hit
This commit adds bans by last LRU time, basically equivalent to the existing
obj.age from b06cdbbab4099a351e188106add56b5e1eb0b927 (the code was trivial to
add).
The primary use case is to remove objects from cache which have not been
accessed for a long time, and, in particular, to get rid of request bans by
removing all objects which have not been touched since the request ban.
diff --git a/bin/varnishd/cache/cache_ban.c b/bin/varnishd/cache/cache_ban.c
index d611445d6..ce54c5c3d 100644
--- a/bin/varnishd/cache/cache_ban.c
+++ b/bin/varnishd/cache/cache_ban.c
@@ -498,8 +498,8 @@ ban_evaluate(struct worker *wrk, const uint8_t *bsarg, struct objcore *oc,
int rv;
/*
- * for ttl and age, fix the point in time such that banning refers to
- * the same point in time when the ban is evaluated
+ * for ttl, age and last_hit, fix the point in time such that banning
+ * refers to the same point in time when the ban is evaluated
*
* for grace/keep, we assume that the absolute values are pola and that
* users will most likely also specify a ttl criterion if they want to
@@ -546,6 +546,12 @@ ban_evaluate(struct worker *wrk, const uint8_t *bsarg, struct objcore *oc,
darg1 = oc->keep;
darg2 = bt.arg2_double;
break;
+ case BANS_ARG_OBJLASTHIT:
+ if (isnan(oc->last_lru))
+ return (0);
+ darg1 = 0.0 - oc->last_lru;
+ darg2 = 0.0 - (ban_time(bsarg) - bt.arg2_double);
+ break;
default:
WRONG("Wrong BAN_ARG code");
}
diff --git a/bin/varnishd/cache/cache_ban.h b/bin/varnishd/cache/cache_ban.h
index d3339eef0..468c54747 100644
--- a/bin/varnishd/cache/cache_ban.h
+++ b/bin/varnishd/cache/cache_ban.h
@@ -97,7 +97,8 @@
#define BANS_ARG_OBJAGE 0x1d
#define BANS_ARG_OBJGRACE 0x1e
#define BANS_ARG_OBJKEEP 0x1f
-#define BANS_ARG_LIM (BANS_ARG_OBJKEEP + 1)
+#define BANS_ARG_OBJLASTHIT 0x20
+#define BANS_ARG_LIM (BANS_ARG_OBJLASTHIT + 1)
#define BAN_ARGIDX(x) ((x) - BANS_ARG_OFF_)
#define BAN_ARGARRSZ (BANS_ARG_LIM - BANS_ARG_OFF_)
@@ -116,7 +117,7 @@
// has an arg2_double (BANS_FLAG_DURATION at build time)
#define BANS_HAS_ARG2_DOUBLE(arg) \
((arg) >= BANS_ARG_OBJTTL && \
- (arg) <= BANS_ARG_OBJKEEP)
+ (arg) <= BANS_ARG_OBJLASTHIT)
/*--------------------------------------------------------------------*/
diff --git a/bin/varnishtest/tests/c00059.vtc b/bin/varnishtest/tests/c00059.vtc
index 410e794a4..4bee69add 100644
--- a/bin/varnishtest/tests/c00059.vtc
+++ b/bin/varnishtest/tests/c00059.vtc
@@ -3,6 +3,9 @@ varnishtest "test ban obj.* except obj.http.*"
# see c00021.vtc for obj.http.* tests
server s1 {
+ rxreq
+ expect req.url == "/old"
+ txresp -status 204
rxreq
txresp -bodylen 1
rxreq
@@ -15,11 +18,25 @@ server s1 {
txresp -bodylen 5
rxreq
txresp -bodylen 6
+ rxreq
+ txresp -bodylen 7
} -start
-varnish v1 -vcl+backend {} -start
+varnish v1 -vcl+backend {
+ sub vcl_deliver {
+ set resp.http.hits = obj.hits;
+ }
+} -start
client c1 {
+ txreq -url "/old"
+ rxresp
+ expect resp.status == 204
+
+ txreq -url "/old"
+ rxresp
+ expect resp.status == 204
+
txreq
rxresp
expect resp.bodylen == 1
@@ -55,7 +72,7 @@ client c1 {
expect resp.bodylen == 2
} -run
-varnish v1 -cliok "ban obj.ttl <= 2m"
+varnish v1 -cliok "ban obj.status == 200 && obj.ttl <= 2m"
client c1 {
txreq
@@ -75,7 +92,7 @@ client c1 {
expect resp.bodylen == 3
} -run
-varnish v1 -cliok "ban obj.age < 1m"
+varnish v1 -cliok "ban obj.status == 200 && obj.age < 1m"
client c1 {
txreq
@@ -95,7 +112,7 @@ client c1 {
expect resp.bodylen == 4
} -run
-varnish v1 -cliok "ban obj.grace == 10s"
+varnish v1 -cliok "ban obj.status == 200 && obj.grace == 10s"
client c1 {
txreq
@@ -115,12 +132,37 @@ client c1 {
expect resp.bodylen == 5
} -run
-varnish v1 -cliok "ban obj.keep == 0s"
+varnish v1 -cli "param.set ban_lurker_age 0.1"
+varnish v1 -cliok "ban obj.status == 200 && obj.keep == 0s"
+delay 1
client c1 {
txreq
rxresp
expect resp.bodylen == 6
+
+ txreq
+ rxresp
+ expect resp.bodylen == 6
+ expect resp.http.hits == 1
+} -run
+
+# now we should have two objects, /old from the beginning and the len==6 object
+varnish v1 -cliexpect { 2 C} "ban.list"
+varnish v1 -cli "param.set ban_lurker_age 600"
+varnish v1 -cliok "ban obj.last_hit < 1s"
+
+# /old survives, but len==6 gets removed
+client c1 {
+ txreq -url "/old"
+ rxresp
+ expect resp.http.age > 0
+ expect resp.http.hits == 2
+
+ txreq
+ rxresp
+ expect resp.bodylen == 7
+ expect resp.http.hits == 0
} -run
# duration formatting - 0s is being tested above
diff --git a/include/tbl/ban_arg_oper.h b/include/tbl/ban_arg_oper.h
index d139e08a6..b118d697c 100644
--- a/include/tbl/ban_arg_oper.h
+++ b/include/tbl/ban_arg_oper.h
@@ -52,6 +52,7 @@ ARGOPER(BANS_ARG_OBJTTL, BANS_OPER_DURATION)
ARGOPER(BANS_ARG_OBJAGE, BANS_OPER_DURATION)
ARGOPER(BANS_ARG_OBJGRACE, BANS_OPER_DURATION)
ARGOPER(BANS_ARG_OBJKEEP, BANS_OPER_DURATION)
+ARGOPER(BANS_ARG_OBJLASTHIT, BANS_OPER_DURATION)
#undef ARGOPER
#undef BANS_OPER_STRING
diff --git a/include/tbl/ban_vars.h b/include/tbl/ban_vars.h
index 015cef817..efafff8ec 100644
--- a/include/tbl/ban_vars.h
+++ b/include/tbl/ban_vars.h
@@ -57,6 +57,9 @@ PVAR("obj.grace",
PVAR("obj.keep",
BANS_FLAG_OBJ | BANS_FLAG_DURATION,
BANS_ARG_OBJKEEP)
+PVAR("obj.last_hit",
+ BANS_FLAG_OBJ | BANS_FLAG_DURATION | BANS_FLAG_NODEDUP,
+ BANS_ARG_OBJLASTHIT)
#undef PVAR
/*lint -restore */
diff --git a/vmod/vmod_std.vcc b/vmod/vmod_std.vcc
index b5ab2a8aa..9320147e8 100644
--- a/vmod/vmod_std.vcc
+++ b/vmod/vmod_std.vcc
@@ -612,10 +612,15 @@ The format of *STRING* is::
* duration fields:
- * ``obj.ttl``: Remaining ttl at the time the ban is issued
- * ``obj.age``: Object age at the time the ban is issued
+ * ``obj.ttl``: Remaining ttl
+ * ``obj.age``: Object age
* ``obj.grace``: The grace time of the object
* ``obj.keep``: The keep time of the object
+ * ``obj.last_hit``: Time since the last hit
+
+ ``obj.ttl``, ``obj.age`` and ``obj.last_hit`` are relative to the submission
+ time of the ban, such that they represent a fixed point in time despite
+ being specified as a duration.
* *<operator>*:
@@ -662,6 +667,19 @@ non-existing header, the operators ``==`` and ``~`` always evaluate as
false, while the operators ``!=`` and ``!~`` always evaluate as true,
respectively, for any value of *<arg>*.
+``obj.last_hit`` can be used almost as a "last accessed" time, so, for example,
+``ban obj.last_hit > 1d`` removes all objects which were last accessed more than
+one day ago. Also, it can be used to remove objects stuck at request bans by
+issuing ``ban obj.last_hit > X``, with X being slightly less than the time since
+the request ban.
+
+``obj.last_hit`` is based on an internal last LRU time, which might not be
+implemented by all storage engines. Where it is not available, ban expressions
+using ``obj.last_hit`` evaluate to ``false``, which means that the respective
+ban behaves as if it was not present. Where implemented, the last LRU time might
+only get updated by the ``lru_interval`` parameter, which therefore is the
+maximum precision of ``obj.last_hit`` bans.
+
$Function STRING ban_error()
Returns a textual error description of the last `std.ban()`_ call from
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