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comparison xml/en/docs/debugging_log.xml @ 1449:c79501e16e26

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Documented cyclic memory buffer support for error_log.
author Yaroslav Zhuravlev <yar@nginx.com>
date Wed, 08 Apr 2015 13:56:52 +0300
parents d3390895fe6e
children 64ed0ce8ac5e
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1448:d3390895fe6e 1449:c79501e16e26
6 <!DOCTYPE article SYSTEM "../../../dtd/article.dtd"> 6 <!DOCTYPE article SYSTEM "../../../dtd/article.dtd">
7 7
8 <article name="A debugging log" 8 <article name="A debugging log"
9 link="/en/docs/debugging_log.html" 9 link="/en/docs/debugging_log.html"
10 lang="en" 10 lang="en"
11 rev="2"> 11 rev="3">
12 12
13 13
14 <section> 14 <section>
15 15
16 <para> 16 <para>
80 </programlisting> 80 </programlisting>
81 </para> 81 </para>
82 82
83 </section> 83 </section>
84 84
85
86 <section id="memory" name="Logging to a cyclic memory buffer">
87
88 <para>
89 The debugging log can be written to a cyclic memory buffer:
90 <programlisting>
91 error_log memory:32m debug;
92 </programlisting>
93 Logging to the memory buffer on the <literal>debug</literal> level
94 does not have significant impact on performance even under high load.
95 In this case, the log can be extracted using
96 a <command>gdb</command> script like the following one:
97 <example>
98 set $log = ngx_cycle->new_log
99
100 while $log.writer != ngx_log_memory_writer
101 set $log = $log.next
102 end
103
104 set $buf = (ngx_buf_t *) $log.wdata
105 dump binary memory log.txt $buf->start $buf->end
106 </example>
107 </para>
108
109 </section>
110
85 </article> 111 </article>