mod_systemd: Add IdleShutdown - number of seconds in idle-state after which

httpd is shutdown. This is useful in a combination with socket activation.
Add mod_systemd documentation.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1618579 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/docs/log-message-tags/next-number b/docs/log-message-tags/next-number
index 9fe34ed6cff3e1596ff581b73261a51ce1806c65..2e4e684632bf7985d90b702dafaae2d40402fb41 100644 (file)
--- a/docs/log-message-tags/next-number
+++ b/docs/log-message-tags/next-number
@@ -1 +1 @@
-2804
+2805

diff --git a/docs/manual/mod/mod_systemd.xml b/docs/manual/mod/mod_systemd.xml
new file mode 100644 (file)
index 0000000..e50d3ce
--- /dev/null
+++ b/docs/manual/mod/mod_systemd.xml
@@ -0,0 +1,70 @@
+<?xml version="1.0"?>
+<!DOCTYPE modulesynopsis SYSTEM "../style/modulesynopsis.dtd">
+<?xml-stylesheet type="text/xsl" href="../style/manual.en.xsl"?>
+<!-- $LastChangedRevision: 1611791 $ -->
+
+<!--
+ Licensed to the Apache Software Foundation (ASF) under one or more
+ contributor license agreements.  See the NOTICE file distributed with
+ this work for additional information regarding copyright ownership.
+ The ASF licenses this file to You under the Apache License, Version 2.0
+ (the "License"); you may not use this file except in compliance with
+ the License.  You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+-->
+
+<modulesynopsis metafile="mod_systemd.xml.meta">
+
+<name>mod_systemd</name>
+<description>Provides better support for systemd integration</description>
+<status>Extension</status>
+<sourcefile>mod_systemd.c</sourcefile>
+<identifier>systemd_module</identifier>
+
+<summary>
+    <p>This module provides support for systemd integration. It allows
+    starting httpd as a service with systemd <code>Type=notify</code>
+    (see systemd.service(5) manual page for more information). It also
+    provides statistics in <code>systemctl status</code> output and adds
+    various directives useful for systemd integration.
+    </p>
+</summary>
+
+<directivesynopsis>
+<name>IdleShutdown</name>
+<description>Enable shutting down the httpd when it is idle for some time.</description>
+<syntax>IdleShutdown seconds</syntax>
+<default>IdleShutdown 0</default>
+<contextlist><context>server config</context></contextlist>
+
+<usage>
+    <p>The <directive>IdleShutdown</directive> directive enables shutting
+    down the httpd when it is idle for some time. The idleness is based on
+    bytes served, so if there are no bytes sent for some time defined by this
+    directive, httpd will shutdown. By default, IdleShutdown is set to 0
+    meaning this feature is disabled.
+    </p>
+
+    <p>This feature is useful in a combination with systemd socket activation
+    (see systemd.socket(5) manual page). When httpd is started by systemd on
+    some request, using this directive you can stop the httpd automatically
+    when all the requests are served.
+    </p>
+
+    <note type="warning"><title>Implementation warning</title><p>
+    Because of implementation details, idleness is checked only every 10
+    seconds. That means that if you specify <code>IdleShutdown 14</code>,
+    httpd will stop itself after 20 seconds of idleness.
+    </p></note>
+</usage>
+</directivesynopsis>
+
+
+</modulesynopsis>

diff --git a/modules/arch/unix/mod_systemd.c b/modules/arch/unix/mod_systemd.c
index fa561519494175144282fd870bb8b7ee748f02f3..6f34fe44d3a3df147c8e687e69447fe0a97a6c44 100644 (file)
--- a/modules/arch/unix/mod_systemd.c
+++ b/modules/arch/unix/mod_systemd.c
@@ -34,15 +34,21 @@
 #include <unistd.h>
 #endif
 
+static int shutdown_timer = 0;
+static int shutdown_counter = 0;
+static unsigned long bytes_served;
+static pid_t mainpid;
+
 static int systemd_pre_mpm(apr_pool_t *p, ap_scoreboard_e sb_type)
 {
     int rv;
 
     ap_extended_status = 1;
+    mainpid = getpid();
 
     rv = sd_notifyf(0, "READY=1\n"
                     "STATUS=Processing requests...\n"
-                    "MAINPID=%" APR_PID_T_FMT, getpid());
+                    "MAINPID=%" APR_PID_T_FMT, mainpid);
     if (rv < 0) {
         ap_log_perror(APLOG_MARK, APLOG_ERR, 0, p, APLOGNO(02395)
                      "sd_notifyf returned an error %d", rv);
@@ -77,6 +83,26 @@ static int systemd_monitor(apr_pool_t *p, server_rec *s)
                      "sd_notifyf returned an error %d", rv);
     }
 
+    /* Shutdown httpd when nothing is sent for shutdown_timer seconds. */
+    if (sload.bytes_served == bytes_served) {
+        shutdown_counter += 10;
+        if (shutdown_timer > 0 && shutdown_counter >= shutdown_timer) {
+            rv = sd_notifyf(0, "READY=1\n"
+                            "STATUS=Stopped as result of IdleShutdown "
+                            "timeout.");
+            if (rv < 0) {
+                ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(02804)
+                            "sd_notifyf returned an error %d", rv);
+            }
+            kill(mainpid, SIGWINCH);
+        }
+    }
+    else {
+        shutdown_counter = 0;
+    }
+
+    bytes_served = sload.bytes_served;
+
     return DECLINED;
 }
 
@@ -88,12 +114,31 @@ static void systemd_register_hooks(apr_pool_t *p)
     ap_hook_monitor(systemd_monitor, NULL, NULL, APR_HOOK_MIDDLE);
 }
 
+static const char *set_shutdown_timer(cmd_parms *cmd, void *dummy,
+                                      const char *arg)
+{
+    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+    if (err != NULL) {
+        return err;
+    }
+
+    shutdown_timer = atoi(arg);
+    return NULL;
+}
+
+static const command_rec systemd_cmds[] =
+{
+AP_INIT_TAKE1("IdleShutdown", set_shutdown_timer, NULL, RSRC_CONF,
+     "Number of seconds in idle-state after which httpd is shutdown"),
+    {NULL}
+};
+
 AP_DECLARE_MODULE(systemd) = {
     STANDARD20_MODULE_STUFF,
     NULL,
     NULL,
     NULL,
     NULL,
-    NULL,
+    systemd_cmds,
     systemd_register_hooks,
 };