Mercurial > hg > nginx
view src/stream/ngx_stream_upstream_round_robin.h @ 7098:7bfbf73db920
Stream: relaxed next upstream condition (ticket #1317).
When switching to a next upstream, some buffers could be stuck in the middle
of the filter chain. A condition existed that raised an error when this
happened. As it turned out, this condition prevented switching to a next
upstream if ssl preread was used with the TCP protocol (see the ticket).
In fact, the condition does not make sense for TCP, since after successful
connection to an upstream switching to another upstream never happens. As for
UDP, the issue with stuck buffers is unlikely to happen, but is still possible.
Specifically, if a filter delays sending data to upstream.
The condition can be relaxed to only check the "buffered" bitmask of the
upstream connection. The new condition is simpler and fixes the ticket issue
as well. Additionally, the upstream_out chain is now reset for UDP prior to
connecting to a new upstream to prevent repeating the client data twice.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Mon, 11 Sep 2017 15:32:31 +0300 |
parents | f41c2530dd17 |
children | 90cc7194e993 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_STREAM_UPSTREAM_ROUND_ROBIN_H_INCLUDED_ #define _NGX_STREAM_UPSTREAM_ROUND_ROBIN_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_stream.h> typedef struct ngx_stream_upstream_rr_peer_s ngx_stream_upstream_rr_peer_t; struct ngx_stream_upstream_rr_peer_s { struct sockaddr *sockaddr; socklen_t socklen; ngx_str_t name; ngx_str_t server; ngx_int_t current_weight; ngx_int_t effective_weight; ngx_int_t weight; ngx_uint_t conns; ngx_uint_t max_conns; ngx_uint_t fails; time_t accessed; time_t checked; ngx_uint_t max_fails; time_t fail_timeout; ngx_msec_t slow_start; ngx_msec_t start_time; ngx_uint_t down; void *ssl_session; int ssl_session_len; #if (NGX_STREAM_UPSTREAM_ZONE) ngx_atomic_t lock; #endif ngx_stream_upstream_rr_peer_t *next; NGX_COMPAT_BEGIN(25) NGX_COMPAT_END }; typedef struct ngx_stream_upstream_rr_peers_s ngx_stream_upstream_rr_peers_t; struct ngx_stream_upstream_rr_peers_s { ngx_uint_t number; #if (NGX_STREAM_UPSTREAM_ZONE) ngx_slab_pool_t *shpool; ngx_atomic_t rwlock; ngx_stream_upstream_rr_peers_t *zone_next; #endif ngx_uint_t total_weight; unsigned single:1; unsigned weighted:1; ngx_str_t *name; ngx_stream_upstream_rr_peers_t *next; ngx_stream_upstream_rr_peer_t *peer; }; #if (NGX_STREAM_UPSTREAM_ZONE) #define ngx_stream_upstream_rr_peers_rlock(peers) \ \ if (peers->shpool) { \ ngx_rwlock_rlock(&peers->rwlock); \ } #define ngx_stream_upstream_rr_peers_wlock(peers) \ \ if (peers->shpool) { \ ngx_rwlock_wlock(&peers->rwlock); \ } #define ngx_stream_upstream_rr_peers_unlock(peers) \ \ if (peers->shpool) { \ ngx_rwlock_unlock(&peers->rwlock); \ } #define ngx_stream_upstream_rr_peer_lock(peers, peer) \ \ if (peers->shpool) { \ ngx_rwlock_wlock(&peer->lock); \ } #define ngx_stream_upstream_rr_peer_unlock(peers, peer) \ \ if (peers->shpool) { \ ngx_rwlock_unlock(&peer->lock); \ } #else #define ngx_stream_upstream_rr_peers_rlock(peers) #define ngx_stream_upstream_rr_peers_wlock(peers) #define ngx_stream_upstream_rr_peers_unlock(peers) #define ngx_stream_upstream_rr_peer_lock(peers, peer) #define ngx_stream_upstream_rr_peer_unlock(peers, peer) #endif typedef struct { ngx_uint_t config; ngx_stream_upstream_rr_peers_t *peers; ngx_stream_upstream_rr_peer_t *current; uintptr_t *tried; uintptr_t data; } ngx_stream_upstream_rr_peer_data_t; ngx_int_t ngx_stream_upstream_init_round_robin(ngx_conf_t *cf, ngx_stream_upstream_srv_conf_t *us); ngx_int_t ngx_stream_upstream_init_round_robin_peer(ngx_stream_session_t *s, ngx_stream_upstream_srv_conf_t *us); ngx_int_t ngx_stream_upstream_create_round_robin_peer(ngx_stream_session_t *s, ngx_stream_upstream_resolved_t *ur); ngx_int_t ngx_stream_upstream_get_round_robin_peer(ngx_peer_connection_t *pc, void *data); void ngx_stream_upstream_free_round_robin_peer(ngx_peer_connection_t *pc, void *data, ngx_uint_t state); #endif /* _NGX_STREAM_UPSTREAM_ROUND_ROBIN_H_INCLUDED_ */