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Diffstat (limited to 'lib/kernel/doc/src/logger_disk_log_h.xml')
| -rw-r--r-- | lib/kernel/doc/src/logger_disk_log_h.xml | 123 |
1 files changed, 66 insertions, 57 deletions
diff --git a/lib/kernel/doc/src/logger_disk_log_h.xml b/lib/kernel/doc/src/logger_disk_log_h.xml index 63c29cb010..c60cf14cc7 100644 --- a/lib/kernel/doc/src/logger_disk_log_h.xml +++ b/lib/kernel/doc/src/logger_disk_log_h.xml @@ -38,101 +38,110 @@ <description> <p>This is a handler for Logger that offers circular (wrapped) logs by using <seealso marker="disk_log"><c>disk_log</c></seealso>. - Multiple instances - of this handler can be added to Logger, and each instance prints to - its own disk_log file, created with the name and settings specified in - the handler configuration.</p> + Multiple instances of this handler can be added to Logger, and each instance + prints to its own disk_log file, created with the name and settings specified + in the handler configuration.</p> <p>The default standard handler, <seealso marker="logger_std_h"><c>logger_std_h</c></seealso>, can be - replaced by a disk_log handler at start up of the Kernel application. + replaced by a disk_log handler at startup of the Kernel application. See an example of this below.</p> - <p>The handler has an overload protection mechanism that will keep the handler - process and the Kernel application alive during a high load of log - requests. How this feature works, and how to modify the configuration, - is described in the + <p>The handler has an overload protection mechanism that keeps the handler + process and the Kernel application alive during high loads of log + events. How overload protection works, and how to configure it, is + described in the <seealso marker="logger_chapter#overload_protection"><c>User's Guide</c> </seealso>.</p> <p>To add a new instance of the disk_log handler, use <seealso marker="logger#add_handler-3"><c>logger:add_handler/3</c> - </seealso>. The handler configuration argument is a map which may contain + </seealso>. The handler configuration argument is a map which can contain general configuration parameters, as documented in the <seealso marker="logger_chapter#handler_configuration"><c>User's Guide</c> - </seealso>, as well as handler specific parameters.</p> - <p>The settings for the disk_log log file should be specified with the - key <c>disk_log_opts</c>. These settings are a subset of the disk_log - data type - <seealso marker="disk_log#open-1"><c>dlog_option()</c></seealso>.</p> - <p>Parameters in the <c>disk_log_opts</c> map:</p> + </seealso>, and handler specific parameters. The specific data + is stored in a sub map with the key <c>config</c>, and can contain the + following parameters:</p> <taglist> <tag><c>file</c></tag> - <item>This is the full name of the disk_log log file.</item> + <item> + <p>This is the full name of the disk_log log file. The option + corresponds to the <c>name</c> property in the + <seealso marker="disk_log#open-1"><c>dlog_option()</c></seealso> + datatype.</p> + </item> <tag><c>type</c></tag> - <item>This is the disk_log type, <c>wrap</c> or <c>halt</c>. The - default value is <c>wrap</c>.</item> + <item> + <p>This is the disk_log type, <c>wrap</c> or <c>halt</c>. The option + corresponds to the <c>type</c> property in the + <seealso marker="disk_log#open-1"><c>dlog_option()</c></seealso> + datatype.</p> + <p>Defaults to <c>wrap</c>.</p> + </item> <tag><c>max_no_files</c></tag> - <item>This is the maximum number of files that disk_log will use - for its circular logging. The default value is <c>10</c>. (The setting - has no effect on a halt log).</item> + <item> + <p>This is the maximum number of files that disk_log will use + for its circular logging. The option + corresponds to the <c>MaxNoFiles</c> element in the <c>size</c> property in the + <seealso marker="disk_log#open-1"><c>dlog_option()</c></seealso> + datatype.</p> + <p>Defaults to <c>10</c>. (The setting has no effect on a halt log).</p> + </item> <tag><c>max_no_bytes</c></tag> - <item>This is the maximum number of bytes that will be written to - a log file before disk_log proceeds with the next file in order (or - generates an error in case of a full halt log). The default value for - a wrap log is <c>1048576</c> bytes, and <c>infinity</c> for a halt - log.</item> - </taglist> - <p>Specific configuration for the handler (represented as a sub map) - is specified with the key <c>config</c>. It may contain the - following parameter:</p> - <taglist> + <item> + <p>This is the maximum number of bytes that will be written to + a log file before disk_log proceeds with the next file in order (or + generates an error in case of a full halt log). The option + corresponds to the <c>MaxNoBytes</c> element in the <c>size</c> property in the + <seealso marker="disk_log#open-1"><c>dlog_option()</c></seealso> + datatype.</p> + <p>Defaults to <c>1048576</c> bytes for a wrap log, and + <c>infinity</c> for a halt log.</p> + </item> <tag><c>filesync_repeat_interval</c></tag> <item> - <p>This value (in milliseconds) specifies how often the handler will - do a disk_log sync operation in order to make sure that buffered data - gets written to disk. The handler will repeatedly attempt this - operation, but only perform it if something has actually been logged - since the last sync. The default value is <c>5000</c> milliseconds. - If <c>no_repeat</c> is set as value, the repeated sync operation is - disabled. The user can also call the - <seealso marker="logger_disk_log_h#sync-1"><c>sync/1</c> - </seealso> function to perform a disk_log sync.</p></item> + <p>This value, in milliseconds, specifies how often the handler does + a disk_log sync operation to write buffered data to disk. The handler attempts + the operation repeatedly, but only performs a new sync if something has + actually been logged.</p> + <p>Defaults to <c>5000</c> milliseconds.</p> + <p>If <c>no_repeat</c> is set as value, the repeated sync operation + is disabled. The user can also call the + <seealso marker="logger_disk_log_h#filesync-1"><c>filesync/1</c> + </seealso> function to perform a disk_log sync.</p> + </item> </taglist> - <p>There are a number of other configuration parameters available, that are - to be used for customizing the overload protection behaviour. The same - parameters are used both in the standard handler and the disk_log handler, - and are documented in the + <p>Other configuration parameters exist, to be used for customizing + the overload protection behaviour. The same parameters are used both in the + standard handler and the disk_log handler, and are documented in the <seealso marker="logger_chapter#overload_protection"><c>User's Guide</c> </seealso>.</p> <p>Note that when changing the configuration of the handler in runtime, by calling <seealso marker="logger#set_handler_config-2"><c>logger:set_handler_config/2 - or logger:set_handler_config/3</c></seealso>, the <c>disk_log_opts</c> - settings may not be modified.</p> + or logger:set_handler_config/3</c></seealso>, the disk_log options (<c>file</c>, + <c>type</c>, <c>max_no_files</c>, <c>max_no_bytes</c>) must not be modified.</p> <p>Example of adding a disk_log handler:</p> <code type="none"> logger:add_handler(my_disk_log_h, logger_disk_log_h, #{level => error, filter_default => log, - disk_log_opts => - #{file => "./my_disk_log", - type => wrap, - max_no_files => 4, - max_no_bytes => 10000}, - config => - #{filesync_repeat_interval => 1000}}). + config => #{file => "./my_disk_log", + type => wrap, + max_no_files => 4, + max_no_bytes => 10000}, + filesync_repeat_interval => 1000}}). </code> - <p>In order to use the disk_log handler instead of the default standard + <p>To use the disk_log handler instead of the default standard handler when starting an Erlang node, change the Kernel default logger to use disk_log. Example:</p> <code type="none"> erl -kernel logger '[{handler,default,logger_disk_log_h, - #{disk_log_opts => #{file => "./system_disk_log"}}}]' + #{config => #{file => "./system_disk_log"}}}]' </code> </description> <funcs> <func> - <name name="sync" arity="1" clause_i="1"/> + <name name="filesync" arity="1" clause_i="1"/> <fsummary>Writes buffered data to disk.</fsummary> <desc> <p>Write buffered data to disk.</p> |