[PATCH] Make random/hash director exhaust the backend list when looking for healthy backend.
Federico Schwindt
fgsch at lodoss.net
Mon Sep 1 13:17:55 CEST 2014
Good point.
Then this looks like I had in mind. OK for me.
On Mon, Sep 1, 2014 at 12:06 PM, Martin Blix Grydeland <
martin at varnish-software.com> wrote:
>
> On 29 August 2014 15:10, Federico Schwindt <fgsch at lodoss.net> wrote:
>
>> Hi,
>>
>> Any reason not to use rr->vd->n_backend directly as the round-robin
>> director does?
>>
>
> The n_backend of the vdir.[ch] is opaque to the director implementations.
> I added the new attribute to keep it that way.
>
> Martin
>
>
>>
>>
>> On Fri, Aug 29, 2014 at 1:48 PM, Martin Blix Grydeland <
>> martin at varnish-software.com> wrote:
>>
>>> Fixes: #1575
>>> ---
>>> bin/varnishtest/tests/r01575.vtc | 56
>>> ++++++++++++++++++++++++++++++++++++++++
>>> lib/libvmod_directors/hash.c | 6 ++---
>>> lib/libvmod_directors/random.c | 6 ++---
>>> lib/libvmod_directors/vdir.c | 2 +-
>>> 4 files changed, 63 insertions(+), 7 deletions(-)
>>> create mode 100644 bin/varnishtest/tests/r01575.vtc
>>>
>>> diff --git a/bin/varnishtest/tests/r01575.vtc
>>> b/bin/varnishtest/tests/r01575.vtc
>>> new file mode 100644
>>> index 0000000..11c82c1
>>> --- /dev/null
>>> +++ b/bin/varnishtest/tests/r01575.vtc
>>> @@ -0,0 +1,56 @@
>>> +varnishtest "#1575 - random director exhaust backend list"
>>> +
>>> +# Add 5 backends to a random director, with the 5th having very low
>>> weight.
>>> +# Mark the first 4 sick, and make sure that the 5th will be selected.
>>> +
>>> +server s1 {
>>> + rxreq
>>> + txresp
>>> +} -start
>>> +
>>> +server s2 {
>>> + rxreq
>>> + txresp
>>> +} -start
>>> +
>>> +server s3 {
>>> + rxreq
>>> + txresp
>>> +} -start
>>> +
>>> +server s4 {
>>> + rxreq
>>> + txresp
>>> +} -start
>>> +
>>> +server s5 {
>>> + rxreq
>>> + txresp
>>> +} -start
>>> +
>>> +varnish v1 -vcl+backend {
>>> + import ${vmod_directors};
>>> + sub vcl_init {
>>> + new rd = directors.random();
>>> + rd.add_backend(s1, 10000);
>>> + rd.add_backend(s2, 10000);
>>> + rd.add_backend(s3, 10000);
>>> + rd.add_backend(s4, 10000);
>>> + rd.add_backend(s5, 1);
>>> + }
>>> +
>>> + sub vcl_backend_fetch {
>>> + set bereq.backend = rd.backend();
>>> + }
>>> +} -start
>>> +
>>> +varnish v1 -cliok "backend.set_health s1 sick"
>>> +varnish v1 -cliok "backend.set_health s2 sick"
>>> +varnish v1 -cliok "backend.set_health s3 sick"
>>> +varnish v1 -cliok "backend.set_health s4 sick"
>>> +
>>> +client c1 {
>>> + txreq
>>> + rxresp
>>> + expect resp.status == 200
>>> +} -run
>>> diff --git a/lib/libvmod_directors/hash.c b/lib/libvmod_directors/hash.c
>>> index afef7ed..090039f 100644
>>> --- a/lib/libvmod_directors/hash.c
>>> +++ b/lib/libvmod_directors/hash.c
>>> @@ -47,7 +47,7 @@ struct vmod_directors_hash {
>>> unsigned magic;
>>> #define VMOD_DIRECTORS_HASH_MAGIC 0xc08dd611
>>> struct vdir *vd;
>>> - unsigned nloops;
>>> + unsigned n_backend;
>>> struct vbitmap *vbm;
>>> };
>>>
>>> @@ -64,7 +64,6 @@ vmod_hash__init(const struct vrt_ctx *ctx, struct
>>> vmod_directors_hash **rrp,
>>> AN(rr);
>>> rr->vbm = vbit_init(8);
>>> AN(rr->vbm);
>>> - rr->nloops = 3; //
>>> *rrp = rr;
>>> vdir_new(&rr->vd, vcl_name, NULL, NULL, rr);
>>> }
>>> @@ -90,6 +89,7 @@ vmod_hash_add_backend(const struct vrt_ctx *ctx,
>>> CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
>>> CHECK_OBJ_NOTNULL(rr, VMOD_DIRECTORS_HASH_MAGIC);
>>> (void)vdir_add_backend(rr->vd, be, w);
>>> + rr->n_backend++;
>>> }
>>>
>>> VCL_BACKEND __match_proto__()
>>> @@ -120,6 +120,6 @@ vmod_hash_backend(const struct vrt_ctx *ctx, struct
>>> vmod_directors_hash *rr,
>>> r = vbe32dec(sha256);
>>> r = scalbn(r, -32);
>>> assert(r >= 0 && r <= 1.0);
>>> - be = vdir_pick_be(rr->vd, r, rr->nloops);
>>> + be = vdir_pick_be(rr->vd, r, rr->n_backend);
>>> return (be);
>>> }
>>> diff --git a/lib/libvmod_directors/random.c
>>> b/lib/libvmod_directors/random.c
>>> index 22f0bb9..8ae36a7 100644
>>> --- a/lib/libvmod_directors/random.c
>>> +++ b/lib/libvmod_directors/random.c
>>> @@ -45,7 +45,7 @@ struct vmod_directors_random {
>>> unsigned magic;
>>> #define VMOD_DIRECTORS_RANDOM_MAGIC 0x4732d092
>>> struct vdir *vd;
>>> - unsigned nloops;
>>> + unsigned n_backend;
>>> struct vbitmap *vbm;
>>> };
>>>
>>> @@ -68,7 +68,7 @@ vmod_rr_getfd(const struct director *dir, struct
>>> busyobj *bo)
>>> CAST_OBJ_NOTNULL(rr, dir->priv, VMOD_DIRECTORS_RANDOM_MAGIC);
>>> r = scalbn(random(), -31);
>>> assert(r >= 0 && r < 1.0);
>>> - be = vdir_pick_be(rr->vd, r, rr->nloops);
>>> + be = vdir_pick_be(rr->vd, r, rr->n_backend);
>>> if (be == NULL)
>>> return (NULL);
>>> return (be->getfd(be, bo));
>>> @@ -87,7 +87,6 @@ vmod_random__init(const struct vrt_ctx *ctx, struct
>>> vmod_directors_random **rrp,
>>> AN(rr);
>>> rr->vbm = vbit_init(8);
>>> AN(rr->vbm);
>>> - rr->nloops = 3; //
>>> *rrp = rr;
>>> vdir_new(&rr->vd, vcl_name, vmod_rr_healthy, vmod_rr_getfd, rr);
>>> }
>>> @@ -113,6 +112,7 @@ vmod_random_add_backend(const struct vrt_ctx *ctx,
>>> CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
>>> CHECK_OBJ_NOTNULL(rr, VMOD_DIRECTORS_RANDOM_MAGIC);
>>> (void)vdir_add_backend(rr->vd, be, w);
>>> + rr->n_backend++;
>>> }
>>>
>>> VCL_BACKEND __match_proto__()
>>> diff --git a/lib/libvmod_directors/vdir.c b/lib/libvmod_directors/vdir.c
>>> index 12268eb..aae7a14 100644
>>> --- a/lib/libvmod_directors/vdir.c
>>> +++ b/lib/libvmod_directors/vdir.c
>>> @@ -186,7 +186,7 @@ vdir_pick_be(struct vdir *vd, double w, unsigned
>>> nloops)
>>> nbe = vd->n_backend;
>>> assert(w >= 0.0 && w < 1.0);
>>> vdir_lock(vd);
>>> - for (l = 0; nbe > 0 && tw > 0.0 && l <nloops; l++) {
>>> + for (l = 0; nbe > 0 && tw > 0.0 && l < nloops; l++) {
>>> u = vdir_pick_by_weight(vd, w * tw, vbm);
>>> be = vd->backend[u];
>>> CHECK_OBJ_NOTNULL(be, DIRECTOR_MAGIC);
>>> --
>>> 2.1.0.rc1
>>>
>>>
>>> _______________________________________________
>>> varnish-dev mailing list
>>> varnish-dev at varnish-cache.org
>>> https://www.varnish-cache.org/lists/mailman/listinfo/varnish-dev
>>>
>>
>>
>
>
> --
> <http://varnish-software.com>*Martin Blix Grydeland*
> Senior Developer | Varnish Software AS
> Cell: +47 21 98 92 60
> We Make Websites Fly!
>
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