Mercurial > hg > nginx-quic
view src/http/modules/ngx_http_split_clients_module.c @ 4622:0dfdc3f732cb
Upstream: fixed ip_hash rebalancing with the "down" flag.
Due to weight being set to 0 for down peers, order of peers after sorting
wasn't the same as without the "down" flag (with down peers at the end),
resulting in client rebalancing for clients on other servers. The only
rebalancing which should happen after adding "down" to a server is one
for clients on the server.
The problem was introduced in r1377 (which fixed endless loop by setting
weight to 0 for down servers). The loop is no longer possible with new
smooth algorithm, so preserving original weight is safe.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 14 May 2012 09:58:07 +0000 |
parents | 834049edae24 |
children | 9c9fbdbe9383 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { uint32_t percent; ngx_http_variable_value_t value; } ngx_http_split_clients_part_t; typedef struct { ngx_http_complex_value_t value; ngx_array_t parts; } ngx_http_split_clients_ctx_t; static char *ngx_conf_split_clients_block(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static char *ngx_http_split_clients(ngx_conf_t *cf, ngx_command_t *dummy, void *conf); static ngx_command_t ngx_http_split_clients_commands[] = { { ngx_string("split_clients"), NGX_HTTP_MAIN_CONF|NGX_CONF_BLOCK|NGX_CONF_TAKE2, ngx_conf_split_clients_block, NGX_HTTP_MAIN_CONF_OFFSET, 0, NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_split_clients_module_ctx = { NULL, /* preconfiguration */ NULL, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ NULL, /* create location configuration */ NULL /* merge location configuration */ }; ngx_module_t ngx_http_split_clients_module = { NGX_MODULE_V1, &ngx_http_split_clients_module_ctx, /* module context */ ngx_http_split_clients_commands, /* module directives */ NGX_HTTP_MODULE, /* module type */ NULL, /* init master */ NULL, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static ngx_int_t ngx_http_split_clients_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data) { ngx_http_split_clients_ctx_t *ctx = (ngx_http_split_clients_ctx_t *) data; uint32_t hash; ngx_str_t val; ngx_uint_t i; ngx_http_split_clients_part_t *part; *v = ngx_http_variable_null_value; if (ngx_http_complex_value(r, &ctx->value, &val) != NGX_OK) { return NGX_OK; } hash = ngx_murmur_hash2(val.data, val.len); part = ctx->parts.elts; for (i = 0; i < ctx->parts.nelts; i++) { ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http split: %uD %uD", hash, part[i].percent); if (hash < part[i].percent || part[i].percent == 0) { *v = part[i].value; return NGX_OK; } } return NGX_OK; } static char * ngx_conf_split_clients_block(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { char *rv; uint32_t sum, last; ngx_str_t *value, name; ngx_uint_t i; ngx_conf_t save; ngx_http_variable_t *var; ngx_http_split_clients_ctx_t *ctx; ngx_http_split_clients_part_t *part; ngx_http_compile_complex_value_t ccv; ctx = ngx_pcalloc(cf->pool, sizeof(ngx_http_split_clients_ctx_t)); if (ctx == NULL) { return NGX_CONF_ERROR; } value = cf->args->elts; ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t)); ccv.cf = cf; ccv.value = &value[1]; ccv.complex_value = &ctx->value; if (ngx_http_compile_complex_value(&ccv) != NGX_OK) { return NGX_CONF_ERROR; } name = value[2]; name.len--; name.data++; var = ngx_http_add_variable(cf, &name, NGX_HTTP_VAR_CHANGEABLE); if (var == NULL) { return NGX_CONF_ERROR; } var->get_handler = ngx_http_split_clients_variable; var->data = (uintptr_t) ctx; if (ngx_array_init(&ctx->parts, cf->pool, 2, sizeof(ngx_http_split_clients_part_t)) != NGX_OK) { return NGX_CONF_ERROR; } save = *cf; cf->ctx = ctx; cf->handler = ngx_http_split_clients; cf->handler_conf = conf; rv = ngx_conf_parse(cf, NULL); *cf = save; if (rv != NGX_CONF_OK) { return rv; } sum = 0; last = 0; part = ctx->parts.elts; for (i = 0; i < ctx->parts.nelts; i++) { sum = part[i].percent ? sum + part[i].percent : 10000; if (sum > 10000) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "percent total is greater than 100%%"); return NGX_CONF_ERROR; } if (part[i].percent) { last += part[i].percent * (uint64_t) 0xffffffff / 10000; part[i].percent = last; } } return rv; } static char * ngx_http_split_clients(ngx_conf_t *cf, ngx_command_t *dummy, void *conf) { ngx_int_t n; ngx_str_t *value; ngx_http_split_clients_ctx_t *ctx; ngx_http_split_clients_part_t *part; ctx = cf->ctx; value = cf->args->elts; part = ngx_array_push(&ctx->parts); if (part == NULL) { return NGX_CONF_ERROR; } if (value[0].len == 1 && value[0].data[0] == '*') { part->percent = 0; } else { if (value[0].data[value[0].len - 1] != '%') { goto invalid; } n = ngx_atofp(value[0].data, value[0].len - 1, 2); if (n == NGX_ERROR || n == 0) { goto invalid; } part->percent = (uint32_t) n; } part->value.len = value[1].len; part->value.valid = 1; part->value.no_cacheable = 0; part->value.not_found = 0; part->value.data = value[1].data; return NGX_CONF_OK; invalid: ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid percent value \"%V\"", &value[0]); return NGX_CONF_ERROR; }