Alarm Logging with TAlh
The -l Command Line Switch
Alarm Logging to
Log-Files - the FileAlarmLogger Plugin
Log File Names
Alarm Logging to a Postgresql Database - the
TAlh uses Qt plugins to log alarms. See the section Installing and
Running TAlh for plugin location.
The Logging Command Line Switch
The command line switch -l specifies which plugin is loaded and which parameters are passed to the
If no -l switch is given alarm logging is not available. A warning message is displayed.
The value of the -l switch may contain a list of comma-separated items or white-space
separated items enclosed in double-quotes. The first item is taken as a plugin name prefix. The other
list items must be name/value pairs of the format <name>=<value>. They are
comma-catenated and the resulting parameter string is passed to the plugin.
If the value of the -l switch contains neither comma nor white space the value is taken as a plugin
TAlh searches for a logging plug-in with the name <prefix>AlarmLogger in the operating
system specific plugin directory.
The TAlh Instance Name
Each running instance of TAlh has an "instance name". By default, the instance name is the base
name of the configuration file name, i.e. the sub-string of the configuration file name before the
The TAlh instance name can be overridden with the command line switch --instance.
Alarm Logging to Log-Files
The TAlh distribution contains a plugin "FileAlarmLogger" which logs to files in a format very
similar to alh. Both an alarm log file and an operator actions log file are written.
The value of the -l switch contains one or two items:
- "File" - the plugin name prefix
- optional log path info of the form "path=<info>". The "path=" part is
If no log path info is given, the log files will be written to the directory which contains the
TAlh configuration file.
At midnight (local time) the FileAlarmLogger plugin will close the log file set and open a new one
with updated date in the name.
Log File Names and Log Directories
The alarm log file has the form:
The operator actions log file has the form:
The <prefix> is set to the TAlh instance name (see above).
Examples for TAlh instance name talh3:
or -l File
on Dec 10, 2016 will result in logfiles
The log files will be created in the directory which contains the configuration file.
on Dec 11, 2016 will result in log files
The log files will be created in the directory /usr1/project/talh/log/
Alarm Logging to a Postgresql Database
The TAlh distribution contains a plugin "PsqlAlarmLogger" which logs to a relational PostgreSQL
The value of the -l switch must contain "Psql" as the first item.
This is followed by the database parameters which can be provided
a) either explicitly as a set of name/value pairs:
server=<database server> port=<tcp/ip port> dbname=<database
schema=<database schema> table=<database table> user=<database login name> user2=<database login password> cash=<list limit>*
b) by specifying a file which contains the name/value pairs:
* The cash parameter sets a limit for the length of logging sets which are transferred to the
logger several times per second. If the logging set has more than <list limit> alarms, the
alarms are cashed, i.e. the list is analyzed and alarms originating from the same PV are dropped with
the exception of the last one. The number of dropped alarms is logged.
This reduces the susceptilbility of TAlh to alarm storms.
Command line examples:
The plugin logs both alarms and operator actions into a database table which is created with the
following SQL statement:
CREATE TABLE alarmlog.test( alarmtime timestamp NOT NULL, logtype_id
integer NOT NULL, pv varchar(100), sevr varchar(10), acks varchar(10), state
varchar(50), ackt varchar (10), val varchar (50), ioctime bigint, msg
CONSTRAINT fk_logtype_id FOREIGN KEY (logtype_id)
REFERENCES alarmlog.logtype (logtype_id)) with OIDS;
The logtype_id column in this table is a foreign key which is provided by a database table
which is created by the following SQL statement
logtype_id integer NOT NULL,
logtype varchar(100) NOT
CONSTRAINT pk_logtype_id PRIMARY KEY (logtype_id)
) with OIDS;
The PsqlAlarmLogger plugin uses the following content of the logtype table:
# select * from logtype order
back to Table of Contents
logtype_id | logtype
1 | alarm
2 | operator actions
3 | alarm handler admin