Nginx1.26.patch and fix raise count does not increase under the TCP check

[mofantor]

• 新增ng1.26.3补丁
• 修改README描述布局（使用markdown）
• 修复在TCP健康检查方法下，Rise Count不增加的问题

原因分析

在tcp检查下，默认keepalive的请求是1，但http等方式的请求再发送请求后，都会增加connection的requests数量，但在tcp连接方式中没有增加，导致tcp连接不会被关闭

// ngx_http_upstream_check_send_handler
  if (ctx->send.pos == ctx->send.last) {
      ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0, "http check send done.");
      peer->state = NGX_HTTP_CHECK_SEND_DONE;
      c->requests++; // http等检查方式中，增加当前连接的请求数量
  }

//ngx_http_upstream_check_clean_event
        if (c->error == 0 &&
            cf->need_keepalive &&
            (c->requests < ucscf->check_keepalive_requests)) // 这里的c->requests永远是0，没有增加，导致不会进入关闭连接
        {
            c->write->handler = ngx_http_upstream_check_dummy_handler;
            c->read->handler = ngx_http_upstream_check_discard_handler;
        } else {
            ngx_close_connection(c);
            peer->pc.connection = NULL;
        }

所以修复措施就是在tcp连接检查没有问题后，增加一次requsets

// ngx_http_upstream_check_peek_handler
    if (ngx_http_upstream_check_peek_one_byte(c) == NGX_OK) {
        ngx_http_upstream_check_status_update(peer, 1);
        c->requests++;   // 增加requests数量
    } else {
        c->error = 1;
        ngx_http_upstream_check_status_update(peer, 0);
    }

[mofantor]

I think the HTTPS health check method you submitted doesn’t have this issue. In the TCP connection, the request count c->requests isn’t incremented after sending the request, which causes the incorrect evaluation in ngx_http_upstream_check_clean_event: c->requests < ucscf->check_keepalive_requests. However, your HTTPS implementation references ngx_http_upstream_check_send_handler, where the requests count is correctly incremented. This ensures that connections exceeding or matching check_keepalive_requests are properly released in ngx_http_upstream_check_clean_event

…

On Fri, 21 Mar 2025 at 17:48, Noel Damps ***@***.***> wrote: @mofantor <https://github.com/mofantor> Saw your patch that reference to not closing tcp connections. Is it possible thats the same error, that I got in my Pull Request pr #281 <#281> ? — Reply to this email directly, view it on GitHub <#282 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A7T5WGYW3RHOB7SB24U4XWT2VPN5XAVCNFSM6AAAAABZM6YJFOVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDONBSHA2DSOJWGM> . You are receiving this because you were mentioned.Message ID: ***@***.***> [image: noeldamps]*noeldamps* left a comment (yaoweibin/nginx_upstream_check_module#282) <#282 (comment)> @mofantor <https://github.com/mofantor> Saw your patch that reference to not closing tcp connections. Is it possible thats the same error, that I got in my Pull Request pr #281 <#281> ? — Reply to this email directly, view it on GitHub <#282 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A7T5WGYW3RHOB7SB24U4XWT2VPN5XAVCNFSM6AAAAABZM6YJFOVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDONBSHA2DSOJWGM> . You are receiving this because you were mentioned.Message ID: ***@***.***>