diff options
| -rw-r--r-- | ChangeLog | 2 | ||||
| -rw-r--r-- | doc/Makefile.am | 2 | ||||
| -rw-r--r-- | doc/manual.html | 13 | ||||
| -rw-r--r-- | doc/rsyslog_conf_global.html | 12 | ||||
| -rw-r--r-- | doc/v4compatibility.html | 77 | ||||
| -rw-r--r-- | runtime/glbl.c | 4 |
6 files changed, 97 insertions, 13 deletions
@@ -1,5 +1,7 @@ --------------------------------------------------------------------------- Version 4.5.1 [DEVEL] (rgerhards), 2009-07-?? +- CONFIG CHANGE: $HUPisRestart default is now "off". We are doing this + to support removal of restart-type HUP in v5. - bugfix: fromhost-ip was sometimes truncated - bugfix: potential segfault when zip-compressed syslog records were received (double free) diff --git a/doc/Makefile.am b/doc/Makefile.am index 62ec7500..3dfc8d3a 100644 --- a/doc/Makefile.am +++ b/doc/Makefile.am @@ -13,7 +13,6 @@ html_files = \ ipv6.html \ log_rotation_fix_size.html \ manual.html \ - man_rsyslogd.html \ modules.html \ property_replacer.html \ rsyslog_ng_comparison.html \ @@ -91,6 +90,7 @@ html_files = \ rsconf1_resetconfigvariables.html \ rsconf1_umask.html \ v3compatibility.html \ + v4compatibility.html \ im3195.html \ netstream.html \ ns_gtls.html \ diff --git a/doc/manual.html b/doc/manual.html index 8a1e4fa0..d473f485 100644 --- a/doc/manual.html +++ b/doc/manual.html @@ -28,12 +28,13 @@ time - even a single mouse click helps. Learn <a href="how2help.html">how to hel Due to popular demand, there is now a <a href="rsyslog_ng_comparison.html">side-by-side comparison between rsyslog and syslog-ng</a>.</p> <p>If you are upgrading from rsyslog v2 or stock sysklogd, -<a href="v3compatibility.html">be -sure to read the rsyslog v3 compatibility document!</a> It will work even +<a href="v3compatibility.html">be sure to read the rsyslog v3 compatibility document</a>, +and if you are upgrading from v3, read the +<a href="v4compatibility.html">rsyslog v4 compatibility document</a>. +<p>Rsyslog will work even if you do not read the doc, but doing so will definitely improve your experience.</p> -<p><span style="font-weight: bold;"></span><b>Follow -the links below for the</b><br></p><ul> - +<p><b>Follow the links below for the</b></p> +<ul> <li><a href="troubleshoot.html">troubleshooting rsyslog problems</a></li> <li><a href="rsyslog_conf.html">configuration file syntax (rsyslog.conf)</a></li> <li><a href="http://www.rsyslog.com/tool-regex">a regular expression checker/generator tool for rsyslog</a></li> @@ -42,7 +43,7 @@ the links below for the</b><br></p><ul> <li><a href="bugs.html">rsyslog bug list</a></li> <li><a href="rsyslog_packages.html"> rsyslog packages</a></li> <li><a href="generic_design.html">backgrounder on -generic syslog application design</a><!-- not good as it currently is ;) <li><a href="contributors.html">contributor "Hall of Fame"</a>--></li> +generic syslog application design</a> <li><a href="modules.html">description of rsyslog modules</a></li> </ul> <p><b>We have some in-depth papers on</b></p> diff --git a/doc/rsyslog_conf_global.html b/doc/rsyslog_conf_global.html index 03842758..1fe72c5f 100644 --- a/doc/rsyslog_conf_global.html +++ b/doc/rsyslog_conf_global.html @@ -129,11 +129,15 @@ our paper on <a href="multi_ruleset.html">using multiple rule sets in rsyslog</a <li><a href="rsconf1_gssforwardservicename.html">$GssForwardServiceName</a></li> <li><a href="rsconf1_gsslistenservicename.html">$GssListenServiceName</a></li> <li><a href="rsconf1_gssmode.html">$GssMode</a></li> -<li>$HUPisRestart [<b>on</b>/off] - if set to on, a HUP is a full daemon restart. This means any queued messages are discarded (depending +<li>$HUPisRestart [on/<b>off</b>] - if set to on, a HUP is a full daemon restart. This means any queued messages are discarded (depending on queue configuration, of course) all modules are unloaded and reloaded. This mode keeps compatible with sysklogd, but is -not recommended for use with rsyslog. To do a full restart, simply stop and start the daemon. The default is "on" for -compatibility reasons. If it is set to "off", a HUP will only close open files. This is a much quicker action and usually -the only one that is needed e.g. for log rotation. <b>It is recommended to set the setting to "off".</b></li> +not recommended for use with rsyslog. To do a full restart, simply stop and start the daemon. The default (since 4.5.1) is "off". +If it is set to "off", a HUP will only close open files. This is a much quicker action and usually +the only one that is needed e.g. for log rotation. <b>Restart-type HUPs (value "on") are depricated</b> +and will go away in rsyslog v5. So it is a good idea to change anything that needs it, now. +Usually that should not be a big issue, as the restart-type HUP can easily be replaced by +something along the lines of "/etc/init.d/rsyslog restart". +</li> <li><a href="rsconf1_includeconfig.html">$IncludeConfig</a></li><li>MainMsgQueueCheckpointInterval <number></li> <li>$MainMsgQueueDequeueSlowdown <number> [number is timeout in <i> micro</i>seconds (1000000us is 1sec!), diff --git a/doc/v4compatibility.html b/doc/v4compatibility.html new file mode 100644 index 00000000..5d877af1 --- /dev/null +++ b/doc/v4compatibility.html @@ -0,0 +1,77 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> +<html><head><title>Compatibility notes for rsyslog v4</title> +</head> +<body> +<h1>Compatibility Notes for rsyslog v4</h1> +<p><small><i>Written by <a href="http://www.gerhards.net/rainer">Rainer Gerhards</a> +(2009-07-15)</i></small></p> +<p>The changes introduced in rsyslog v4 are numerous, but not very intrusive. +This document describes things to keep in mind when moving from v3 to v4. It +does not list enhancements nor does it talk about compatibility concerns introduced +by v3 (for this, see the <a href="v3compatibility.html">rsyslog v3 compatibility notes</a>). +<h2>HUP processing</h2> +<p>With v3 and below, rsyslog used the traditional HUP behaviour. That meant that +all output files are closed and the configuration file is re-read and the new configuration +applied. +<p>With a program as simple and static as sysklogd, this was not much of an issue. The +most important config settings (like udp reception) of a traditional syslogd can not be +modified via the configuration file. So a config file reload only meant setting up a new set of filters. It also didn't account as problem that while doing so messages may be lost - without +any threading and queuing model, a traditional syslogd will potentially always loose +messages, so it is irrelevant if this happens, too, during the short config re-read +phase. +<p>In rsyslog, things are quite different: the program is more or less a framework into +which loadable modules are loaded as needed for a particular configuration. The software +that will acutally be running is taylored via the config file. Thus, a re-read of +the config file requires a full, very heavy restart, because the software acutally +running with the new config can be totally different from what ran with the old config. +<p>Consequently, the traditional HUP is a very heavy operation and may even cause some +data loss because queues must be shut down, listeners stopped and so on. Some of these +operations (depending on their configuration) involve intentional message loss. The operation +also takes up a lot of system resources and needs quite some time (maybe seconds) to be +completed. During this restart period, the syslog subsytem is not fully available. +<p>From the software developer's point of view, the full restart done by a HUP is rather complex, +especially if user-timeout limits set on action completion are taken into consideration (for +those in the know: at the extreme ends this means we need to cancel threads as a last resort, +but than we need to make sure that such cancellation does not happen at points where it +would be fatal for a restart). A regular restart, where the process is actually terminated, is +much less complex, because the operating system does a full cleanup after process termination, +so rsyslogd does not need to take care for exotic cleanup cases and leave that to the OS. +In the end result, restart-type HUPs clutter the code, increase complexity (read: add bugs) +and cost performance. +<p>On the contrary, a HUP is typically needed for log rotation, and the real desire is +to close files. This is a non-disruptive and very lightweigth operation. +<p>Many people have said that they are used to HUP the syslogd to apply configuration +changes. This is true, but it is questionable if that really justifies all the cost that +comes with it. After all, it is the difference between typing +<pre> +$ kill -HUP `cat /var/run/rsyslogd.pid` +</pre> +versus +<pre> +$ /etc/init.d/rsyslog restart +</pre> +Semantically, both is mostly the same thing. The only difference is that with the restart +command rsyslogd can spit config error message to stderr, so that the user is able to see +any problems and fix them. With a HUP, we do not have access to stderr and thus can log +error messages only to their configured destinations; exprience tells that most users +will never find them there. What, by the way, is another strong argument against +restarting rsyslogd by HUPing it. +<p>So a restart via HUP is not strictly necessary +and most other deamons require that a restart command is typed in if a restart is required. +<p>Rsyslog will follow this paradigm in the next versions, resulting in many benefits. In v4, +we provide some support for the old-style semantics. We introduced a setting $HUPisRestart +which may be set to "on" (tradional, heavy operationg) +or "off" (new, lightweight "file close only" operation). +The initial versions had the default set to traditional behavior, but starting with 4.5.1 +we are now using the new behavior as the default. +<p>Most importantly, <b>this may break some scripts</b>, but my sincere belief is that +there are very few scripts that automatically <b>change</b> rsyslog's config and then do a +HUP to reload it. Anyhow, if you have some of these, it may be a good idea to change +them now instead of turning restart-type HUPs on. Other than that, one mainly needs +to change the habit of how to restart rsyslog after a configuration change. +<p><b>Please note that restart-type HUP is depricated and will go away in rsyslog v5.</b> +So it is a good idea to become ready for the new version now and also enjoy some of the +benefits of the "real restart", like the better error-reporting capability. +<p>Note that code complexity reduction (and thus performance improvement) needs the restart-type +HUP code to be removed, so these changes can (and will) only happen in version 5. +</body></html> diff --git a/runtime/glbl.c b/runtime/glbl.c index 32b85622..7fa61963 100644 --- a/runtime/glbl.c +++ b/runtime/glbl.c @@ -55,7 +55,7 @@ DEFobjCurrIf(prop) */ static uchar *pszWorkDir = NULL; static int bOptimizeUniProc = 1; /* enable uniprocessor optimizations */ -static int bHUPisRestart = 1; /* should SIGHUP cause a full system restart? */ +static int bHUPisRestart = 0; /* should SIGHUP cause a full system restart? */ static int bPreserveFQDN = 0; /* should FQDNs always be preserved? */ static int iMaxLine = 2048; /* maximum length of a syslog message */ static int iDefPFFamily = PF_UNSPEC; /* protocol family (IPv4, IPv6 or both) */ @@ -293,7 +293,7 @@ static rsRetVal resetConfigVariables(uchar __attribute__((unused)) *pp, void __a } bDropMalPTRMsgs = 0; bOptimizeUniProc = 1; - bHUPisRestart = 1; + bHUPisRestart = 0; bPreserveFQDN = 0; return RS_RET_OK; } |