From db6870e06dde7ab249e9a41a0e0a76219f82dd8c Mon Sep 17 00:00:00 2001 From: Ruslan Ermilov Date: Sat, 15 Feb 2014 15:12:34 +0400 Subject: Upstream: re-resolvable servers. Specifying the upstream server by a hostname together with the "resolve" parameter will make the hostname to be periodically resolved, and upstream servers added/removed as necessary. This requires a "resolver" at the "http" configuration block. The "resolver_timeout" parameter also affects when the failed DNS requests will be attempted again. Responses with NXDOMAIN will be attempted again in 10 seconds. Upstream has a configuration generation number that is incremented each time servers are added/removed to the primary/backup list. This number is remembered by the peer.init method, and if peer.get detects a change in configuration, it returns NGX_BUSY. Each server has a reference counter. It is incremented by peer.get and decremented by peer.free. When a server is removed, it is removed from the list of servers and is marked as "zombie". The memory allocated by a zombie peer is freed only when its reference count becomes zero. Co-authored-by: Roman Arutyunyan Co-authored-by: Sergey Kandaurov Co-authored-by: Vladimir Homutov --- src/http/modules/ngx_http_upstream_ip_hash_module.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'src/http/modules/ngx_http_upstream_ip_hash_module.c') diff --git a/src/http/modules/ngx_http_upstream_ip_hash_module.c b/src/http/modules/ngx_http_upstream_ip_hash_module.c index 1fa01d95a..1c1b41d19 100644 --- a/src/http/modules/ngx_http_upstream_ip_hash_module.c +++ b/src/http/modules/ngx_http_upstream_ip_hash_module.c @@ -163,11 +163,19 @@ ngx_http_upstream_get_ip_hash_peer(ngx_peer_connection_t *pc, void *data) ngx_http_upstream_rr_peers_rlock(iphp->rrp.peers); - if (iphp->tries > 20 || iphp->rrp.peers->single) { + if (iphp->tries > 20 || iphp->rrp.peers->number < 2) { ngx_http_upstream_rr_peers_unlock(iphp->rrp.peers); return iphp->get_rr_peer(pc, &iphp->rrp); } +#if (NGX_HTTP_UPSTREAM_ZONE) + if (iphp->rrp.peers->config && iphp->rrp.config != *iphp->rrp.peers->config) + { + ngx_http_upstream_rr_peers_unlock(iphp->rrp.peers); + return iphp->get_rr_peer(pc, &iphp->rrp); + } +#endif + now = ngx_time(); pc->cached = 0; @@ -232,6 +240,7 @@ ngx_http_upstream_get_ip_hash_peer(ngx_peer_connection_t *pc, void *data) } iphp->rrp.current = peer; + ngx_http_upstream_rr_peer_ref(iphp->rrp.peers, peer); pc->sockaddr = peer->sockaddr; pc->socklen = peer->socklen; @@ -268,6 +277,7 @@ ngx_http_upstream_ip_hash(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) uscf->peer.init_upstream = ngx_http_upstream_init_ip_hash; uscf->flags = NGX_HTTP_UPSTREAM_CREATE + |NGX_HTTP_UPSTREAM_MODIFY |NGX_HTTP_UPSTREAM_WEIGHT |NGX_HTTP_UPSTREAM_MAX_CONNS |NGX_HTTP_UPSTREAM_MAX_FAILS -- cgit