Add s6-svdt-clear, s6-permafailon

author: Laurent Bercot <ska-skaware@skarnet.org> 2018-03-21 18:00:10 +0000
committer: Laurent Bercot <ska-skaware@skarnet.org> 2018-03-21 18:00:10 +0000
commit: 75c4223a7f5a8a073ba0d898ef9d841fdaef2f63 (patch)
tree: d024c08659674117134314e67b4ff825ae51c1d9 /doc
parent: 91eba4b27017c3b7bf0d0bb548a12a694ed51a3b (diff)
download: s6-75c4223a7f5a8a073ba0d898ef9d841fdaef2f63.tar.xz
6 files changed, 170 insertions, 5 deletions
diff --git a/doc/index.html b/doc/index.html
index 733e3ee..bae4da6 100644
--- a/doc/index.html
+++ b/doc/index.html
@@ -157,6 +157,8 @@ a user interface to control those processes and monitor service states.
 <li><a href="s6-svlisten.html">The <tt>s6-svlisten</tt> program</a></li>
 <li><a href="s6-notifyoncheck.html">The <tt>s6-notifyoncheck</tt> program</a></li>
 <li><a href="s6-svdt.html">The <tt>s6-svdt</tt> program</a></li>
+<li><a href="s6-svdt-clear.html">The <tt>s6-svdt-clear</tt> program</a></li>
+<li><a href="s6-permafailon.html">The <tt>s6-permafailon</tt> program</a></li>
 </ul>
 
 <h4> Daemontools-like utilities </h4>
diff --git a/doc/s6-permafailon.html b/doc/s6-permafailon.html
new file mode 100644
index 0000000..f749d5f
--- /dev/null
+++ b/doc/s6-permafailon.html
@@ -0,0 +1,98 @@
+<html>
+  <head>
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
+    <meta http-equiv="Content-Language" content="en" />
+    <title>s6: the s6-permafailon program</title>
+    <meta name="Description" content="s6: the s6-permafailon program" />
+    <meta name="Keywords" content="s6 supervision finish permanent failure service" />
+    <!-- <link rel="stylesheet" type="text/css" href="//skarnet.org/default.css" /> -->
+  </head>
+<body>
+
+<p>
+<a href="index.html">s6</a><br />
+<a href="//skarnet.org/software/">Software</a><br />
+<a href="//skarnet.org/">skarnet.org</a>
+</p>
+
+<h1> The <tt>s6-permafailon</tt> program </h1>
+
+<p>
+<tt>s6-permafailon</tt> is a program that is meant to be used
+in the <tt>./finish</tt> script of a
+<a href="servicedir.html">service directory</a> supervised by
+<a href="s6-supervise.html">s6-supervise</a>. When used, it
+reads and analyses the death tally of a service (i.e. the recent
+process death events that happened), and if the death tally
+matches a given pattern, it causes <em>permanent failure</em>
+of the service, i.e. it tells the supervisor not to try and
+restart it.
+</p>
+
+<h2> Interface </h2>
+
+<pre>
+     s6-permafailon <em>secs</em> <em>deathcount</em> <em>events</em> <em>prog...</em>
+</pre>
+
+<ul>
+ <li> <tt>s6-permafailon</tt> must have the service directory of the
+tested service as its current directory. This is the default if it is
+called from the <tt>finish</tt> script of the service. </li>
+ <li> It reads the <em>death tally</em> of the service, which is
+maintained by <a href="s6-supervise.html">s6-supervise</a>. </li>
+ <li> If the supervised process has died at least <em>deathcount</em>
+times in the last <em>secs</em> seconds with a cause listed in
+<em>events</em>, then <tt>s6-permafailon</tt> exits 125. </li>
+ <li> Else <tt>s6-permafailon</tt> execs into <em>prog...</em>. </li>
+</ul>
+
+<p>
+ <em>events</em> is a comma-separated list of events. An event can be
+one of the following:
+</p>
+
+<ul>
+ <li> An exit code, which is an integer between 0 and 255. Example: <tt>1</tt> </li>
+ <li> An exit code interval, which is two exit codes separated by a dash. Example: <tt>1-50</tt> </li>
+ <li> A signal name, or a signal number preceded by "SIG". Examples: <tt>SIGTERM</tt>, <tt>sigabrt</tt>, <tt>sig11</tt> </li>
+</ul>
+
+<h2> Usage </h2>
+
+<ul>
+  <li> <a href="s6-supervise.html">s6-supervise</a> detects when the <tt>./finish</tt>
+script of its service exits 125, and stops respawning the service. So, if the
+<tt>./finish</tt> script is a chain-loading command line starting with a
+<tt>s6-permafailon</tt> invocation (or containing such an invocation), when
+<tt>s6-permafailon</tt> exits 125, then the <tt>./finish</tt> script also
+exits 125 (because it is the same process), and the service is then marked as
+failing permanently. </li>
+ <li> The <tt>./finish</tt> script is <em>naturally</em> a chain-loading
+command line if it is written in the
+<a href="//skarnet.org/software/execline/">execline</a> language. It
+can also be made into a chain-loading command line from a shell script by using
+<tt>exec s6-permafailon secs deathcount events rest-of-chainloading-cmdline...</tt> </li>
+ <li> Multiple invocations of <tt>s6-permafailon</tt> can be chained, in order
+to test several death patterns. </li>
+ <li> If a permanent failure is triggered and <em>secs</em> is high, it is
+possible that when the administrator manually launches the service again,
+the next death triggers a permanent failure again. If this is not wanted,
+the administrator should clear the death tally with the
+<a href="s6-svdt-clear.html">s6-svdt-clear</a> command. </li>
+ <li> The current death tally can be viewed via the <a href="s6-svdt.html">s6-svdt</a>
+command. </li>
+</ul>
+
+<h2> Example </h2>
+
+<p>
+ <tt>s6-permafailon 60 5 1,101-103,SIGSEGV,SIBBUS <em>prog...</em></tt>
+will exit 125 if the service has died 5 times in the last 60 seconds with
+an exit code of 1, 101, 102 or 103, a SIGSEGV or a SIGBUS. Else it will
+chainload into the <em>prog...</em> command line.
+</p>
+
+</body>
+</html>
diff --git a/doc/s6-svdt-clear.html b/doc/s6-svdt-clear.html
new file mode 100644
index 0000000..e69a1ae
--- /dev/null
+++ b/doc/s6-svdt-clear.html
@@ -0,0 +1,58 @@
+<html>
+  <head>
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
+    <meta http-equiv="Content-Language" content="en" />
+    <title>s6: the s6-svdt-clear program</title>
+    <meta name="Description" content="s6: the s6-svdt-clear program" />
+    <meta name="Keywords" content="s6 command s6-svdt-clear servicedir death tally clearing process supervision s6-supervise" />
+    <!-- <link rel="stylesheet" type="text/css" href="//skarnet.org/default.css" /> -->
+  </head>
+<body>
+
+<p>
+<a href="index.html">s6</a><br />
+<a href="//skarnet.org/software/">Software</a><br />
+<a href="//skarnet.org/">skarnet.org</a>
+</p>
+
+<h1> The <tt>s6-svdt-clear</tt> program </h1>
+
+<p>
+<tt>s6-svdt-clear</tt> clears the recorded death tally of a service.
+</p>
+
+<h2> Interface </h2>
+
+<pre>
+     s6-svdt-clear <em>servicedir</em>
+</pre>
+
+<p>
+ s6-svdt-clear clears the recorded death tally of the service being
+currently supervised at the <em>servicedir</em>
+<a href="servicedir.html">service directory</a>.
+</p>
+
+<ul>
+ <li> 0: success </li>
+ <li> 100: wrong usage </li>
+ <li> 111: system call failed </li>
+</ul>
+
+<h2> Notes </h2>
+
+<ul>
+ <li> Use of <tt>s6-svdt-clear</tt> impacts the listings obtained
+by the <a href="s6-svdt.html">s6-svdt</a> command. </li>
+ <li> It also impacts the behaviour of the
+<a href="s6-permafailon.html">s6-permafailon</a> command. This is
+the main reason to use <tt>s6-svdt-clear</tt>: once a service has
+failed permanently due to an excessive number of deaths in a given
+time, it can be useful to erase that record of deaths before
+starting the service again, in order to avoid permanently failing
+again too fast. </li>
+</ul>
+
+</body>
+</html>
diff --git a/doc/s6-svdt.html b/doc/s6-svdt.html
index a908d8c..f069536 100644
--- a/doc/s6-svdt.html
+++ b/doc/s6-svdt.html
@@ -16,10 +16,10 @@
 <a href="//skarnet.org/">skarnet.org</a>
 </p>
 
-<h1> The s6-svdt program </h1>
+<h1> The <tt>s6-svdt</tt> program </h1>
 
 <p>
-s6-svstat prints the recorded death tally of a service, i.e. a list of the times
+<tt>s6-svdt</tt> prints the recorded death tally of a service, i.e. a list of the times
 the process died, with the cause of death.
 </p>
 
@@ -30,7 +30,7 @@ the process died, with the cause of death.
 </pre>
 
 <p>
- s6-svdt prints the contents of the recorded death tally of the service being
+ <tt>s6-svdt</tt> prints the contents of the recorded death tally of the service being
 currently supervised at the <em>servicedir</em>
 <a href="servicedir.html">service directory</a>, then exits 0.
 </p>
diff --git a/doc/s6-svstat.html b/doc/s6-svstat.html
index a77f903..d40ec3b 100644
--- a/doc/s6-svstat.html
+++ b/doc/s6-svstat.html
@@ -76,8 +76,11 @@ are as follows.
 names are the following:
   <ul>
    <li> <tt>up</tt>: print <tt>true</tt> if the service is up and <tt>false</tt> if it is down.
+<!--
 If the service is being throttled (i.e. technically up, but sleeping for a certain
-amount of time before it is really launched), it prints <tt>throttled</tt> instead of <tt>true</tt>. </li>
+amount of time before it is really launched), it prints <tt>throttled</tt> instead of <tt>true</tt>.
+-->
+ </li>
    <li> <tt>wantedup</tt>: print <tt>true</tt> if <a href="s6-supervise.html">s6-supervise</a>
 is currently instructed to (re)start the service when it is down, and <tt>false</tt> if
 <a href="s6-supervise.html">s6-supervise</a> is currently instructed to leave the service alone. </li>
diff --git a/doc/upgrade.html b/doc/upgrade.html
index 10f139b..c57156d 100644
--- a/doc/upgrade.html
+++ b/doc/upgrade.html
@@ -22,7 +22,11 @@
 
 <ul>
  <li> skalibs dependency bumped to 2.6.4.0. </li>
- <li> New command: <a href="s6-svdt.html">s6-svdt</a>. </li>
+ <li> New commands: <a href="s6-svdt.html">s6-svdt</a>,
+<a href="s6-svdt-clear.html">s6-svdt-clear</a>,
+<a href="s6-permafailon.html">s6-permafailon</a> </li>
+ <li> <a href="s6-tai64nlocal.html">s6-tai64nlocal</a> can now
+print GMT times with the <tt>-g</tt> option. </li>
 </ul>
 
 <h2> in 2.7.0.0 </h2>
author	Laurent Bercot <ska-skaware@skarnet.org>	2018-03-21 18:00:10 +0000
committer	Laurent Bercot <ska-skaware@skarnet.org>	2018-03-21 18:00:10 +0000
commit	75c4223a7f5a8a073ba0d898ef9d841fdaef2f63 (patch)
tree	d024c08659674117134314e67b4ff825ae51c1d9 /doc
parent	91eba4b27017c3b7bf0d0bb548a12a694ed51a3b (diff)
download	s6-75c4223a7f5a8a073ba0d898ef9d841fdaef2f63.tar.xz