Sybase transaction log

Sybase transaction log

Purpose

The transaction log file contains information that allows Sybase to recover from a system failure. The transaction log is also required for auditing. 
Sybase IQ records in the transaction log the information necessary to recover from a system failure.
Although the information logged is small for each committed transaction, the transaction log continues to grow in size.
In systems with a high number of transactions that change data, over a period of time the log can grow to be very large.
It becomes then crucial being able to monitor some transaction log key factors such as the number of log pages already used,
the number of log pages reserved for rollbacks or the number of log pages that has not been used yet.

Monitor features include :

Monitoring transaction log free pages, used pages and CLR pages
Choice of the unit of measure you want to set to monitor all the items : KB, MB, GB, number of pages, or expressed in percentage values.
Setting a muIti threshold alarm policy for every monitored item and to alert in case a threshold is reached

Configuration hints

Unit of measure of the monitor:
Select the unit of measure you want the monitor to fetch monitored features data, it includes : KB, MB, GB, PAGES

Surveillance table:

This is a table of rules that you can use to configure and customize the configuration.
Each line of the table will define a rule of monitoring. You can combine multiple rules to cover different cases.
Within a rule, you can configure the feature you want to monitor (Free pages, Used pages, CLR pages), a multi-threshold value for the selected feature and the the unit of measure of the threshold

Monitored feature :
Select the specific Sybase transaction log feature you want to monitor (Free pages, Used pages, CLR Pages)

Feature threshold :

Use the multi-threshold syntax to set multiple threshold/severity associations: G2W:50 W2M:80 M2C:90 (Green To Warning, Warning To Major, etc…), expressed as the monitor Unit of measure or as percentage values
An alarm of the corresponding severity will be sent if the monitored feature is over or under threshold (depending on what is being monitored).
Set 0 in the field if unused
When setting the multi-thread threshold, notice that for used pages the lower better policy will apply, for free pages and CLR pages a higher better policy.

Unit :
Select “As monitor” if you want to monitor data expressed in the same unit of measure as the monitor or select “Percentage” if you prefer values to be monitored this way.

Atomic fields

Unit of measure	Select the unit of measure you want the monitor to fetch the requested information (KB, MB, GB, Pages)

Surveillance table

Parameter	Description
Active	Use this field to activate or deactivate a line of configuration.
Monitored feature	select one of the supported features : Free pages, Used pages, CLR pages
Feature threshold	The threshold setting for the selected feature You can use the multi threshold syntax (i.e. : G2W:40 W2C:5) .
Unit	Select “As monitor” if threshold values are expressed in the monitor generic Unit of measure - see “Unit of measure” in the Atomic fields section - , or select “Percentage” if threshold setting are expressed as percentage values
Auto clear	If checked, the alarm will be cleared as soon as the alarm condition is not met anymore.
Alarm tag	This field allows to add custom text within the alarm message. %MSG% variable will contain the actual generated message and can be used such as: “my_prefix %MSG% my_suffix”. By default, tag will be used as prefix.
Alarm	If checked, this line of surveillance will be used for alarm generation.
Metric	If checked, this line of surveillance will be used for metric generation.
Report	If checked, this line of surveillance will used for showing threshold and severity in the daily report

Examples

Active	Monitored feature	Feature threshold	Unit	Auto clear	Alarm tag	Alarm	Metric	Report
true	Used pages	G2W:70 W2C:85	Percentage	true		true	true	true

Effect : For this rule, used pages within the trasaction log file will be monitored

A WARNING alarm is sent if used pages are monitored at 70% or more, a CRITICAL alarm if 85% or more.

Generated metrics

metricId	metricUnit	metricTarget	metricDescription
SAP_DATABASE_TRANS_LOG_CLR_PAGES_KB	KB	CLR_PAGES	fetched CLR pages value, expressed in KB
SAP_DATABASE_TRANS_LOG_CLR_PAGES_MB	MB	CLR_PAGES	fetched CLR pages value, expressed in MB
SAP_DATABASE_TRANS_LOG_CLR_PAGES_GB	GB	CLR_PAGES	fetched CLR pages value, expressed in GB
SAP_DATABASE_TRANS_LOG_CLR_PAGES_NUMBER	Number of pages	CLR_PAGES	fetched CLR pages value, expressed in number of pages
SAP_DATABASE_TRANS_LOG_CLR_PAGES_PERCENT	Percentage	CLR_PAGES	fetched CLR pages value, expressed in percentage
SAP_DATABASE_TRANS_LOG_FREE_PAGES_KB	KB	FREE_PAGES	fetched free pages value, expressed in KB
SAP_DATABASE_TRANS_LOG_FREE_PAGES_MB	MB	FREE_PAGES	fetched free pages value, expressed in MB
SAP_DATABASE_TRANS_LOG_FREE_PAGES_GB	GB	FREE_PAGES	fetched free pages value, expressed in GB
SAP_DATABASE_TRANS_LOG_FREE_PAGES_NUMBER	Number of pages	FREE_PAGES	fetched free pages value, expressed in number of pages
SAP_DATABASE_TRANS_LOG_FREE_PAGES_PERCENT	Percentage	FREE_PAGES	fetched free pages value, expressed in percentage
SAP_DATABASE_TRANS_LOG_USED_PAGES_KB	KB	USED_PAGES	fetched used pages value, expressed in KB
AP_DATABASE_TRANS_LOG_USED_PAGES_MB	MB	USED_PAGES	fetched used pages value, expressed in MB
SAP_DATABASE_TRANS_LOG_USED_PAGES_GB	GB	USED_PAGES	fetched used pages value, expressed in GB
SAP_DATABASE_TRANS_LOG_USED_PAGES_NUMBER	Number of pages	USED_PAGES	fetched used pages value, expressed in number of pages
SAP_DATABASE_TRANS_LOG_USED_PAGES_PERCENT	Percentage	USED_PAGES	fetched used pages value, expressed in percentage value

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