From a10ec2db91b448029968025d23155e9c383f522d Mon Sep 17 00:00:00 2001 From: Maxim Dounin Date: Thu, 5 Oct 2017 17:42:59 +0300 Subject: [PATCH] Upstream hash: limited number of tries in consistent case. While this may result in non-ideal distribution of requests if nginx won't be able to select a server in a reasonable number of attempts, this still looks better than severe performance degradation observed if there is no limit and there are many points configured (ticket #1030). This is also in line with what we do for other hash balancing methods. --- src/http/modules/ngx_http_upstream_hash_module.c | 10 +++++++--- src/stream/ngx_stream_upstream_hash_module.c | 10 +++++++--- 2 files changed, 14 insertions(+), 6 deletions(-) diff --git a/src/http/modules/ngx_http_upstream_hash_module.c b/src/http/modules/ngx_http_upstream_hash_module.c index 6c28c6456..78e672c0f 100644 --- a/src/http/modules/ngx_http_upstream_hash_module.c +++ b/src/http/modules/ngx_http_upstream_hash_module.c @@ -503,6 +503,11 @@ ngx_http_upstream_get_chash_peer(ngx_peer_connection_t *pc, void *data) ngx_http_upstream_rr_peers_wlock(hp->rrp.peers); + if (hp->tries > 20 || hp->rrp.peers->single) { + ngx_http_upstream_rr_peers_unlock(hp->rrp.peers); + return hp->get_rr_peer(pc, &hp->rrp); + } + pc->cached = 0; pc->connection = NULL; @@ -577,10 +582,9 @@ ngx_http_upstream_get_chash_peer(ngx_peer_connection_t *pc, void *data) hp->hash++; hp->tries++; - if (hp->tries >= points->number) { - pc->name = hp->rrp.peers->name; + if (hp->tries > 20) { ngx_http_upstream_rr_peers_unlock(hp->rrp.peers); - return NGX_BUSY; + return hp->get_rr_peer(pc, &hp->rrp); } } diff --git a/src/stream/ngx_stream_upstream_hash_module.c b/src/stream/ngx_stream_upstream_hash_module.c index cb44fcdad..413537989 100644 --- a/src/stream/ngx_stream_upstream_hash_module.c +++ b/src/stream/ngx_stream_upstream_hash_module.c @@ -505,6 +505,11 @@ ngx_stream_upstream_get_chash_peer(ngx_peer_connection_t *pc, void *data) ngx_stream_upstream_rr_peers_wlock(hp->rrp.peers); + if (hp->tries > 20 || hp->rrp.peers->single) { + ngx_stream_upstream_rr_peers_unlock(hp->rrp.peers); + return hp->get_rr_peer(pc, &hp->rrp); + } + pc->connection = NULL; now = ngx_time(); @@ -578,10 +583,9 @@ ngx_stream_upstream_get_chash_peer(ngx_peer_connection_t *pc, void *data) hp->hash++; hp->tries++; - if (hp->tries >= points->number) { - pc->name = hp->rrp.peers->name; + if (hp->tries > 20) { ngx_stream_upstream_rr_peers_unlock(hp->rrp.peers); - return NGX_BUSY; + return hp->get_rr_peer(pc, &hp->rrp); } }