Spotlight on SAP ASE 2.12 - User Guide

Data Cache Writes Alarm

This alarm is raised when the rate of physical writes requested by the data cache (expressed as writes per second) exceeds normal levels.

Since this metric is included in calibration, the maximum value, and thereby the alarm thresholds and flow speed, are determined by statistical sampling.

Use this data, along with Cache Searches, to determine how effective the overall cache design for this server is.

Use the Memory drilldown | Data Cache Page to find out which cache has the most utilization. After investigation you may decide that a separate named cache should be created to alleviate any detected contention.

Deadlocks Alarm

This alarm is raised when the number of server-side deadlocks detected on the ASE goes above normal values.

Since this metric is included in calibration, the maximum value, and thereby the alarm thresholds, are determined by statistical sampling.

Deadlocks become more common as lock contention increases.

Things to check:

• Deadlock Detail &endash; see what users and objects are involved (Locks drilldown Deadlock page) (available only on ASE version 12.5.0.3 and newer)

• Investigate whether any long running transactions are running at the same time against the same database (User Activity drilldown)

• Increase in user activity (User Activity drilldown)

• Unexpected hot objects (Locks drilldown and Databases drilldown)

• Lock Contention (Locks Used and Locks Waiting)

Look at ways to improve deadlock occurrences by a variety of options: changing the locking scheme, avoiding table locks, and not holding shared locks.

See the Locks drilldown for detailed information about locks that are in place on the Adaptive Server in general.

See the Locks drilldown | Deadlocks page for detailed information about deadlocks. (Available only on ASE version 12.5.0.3 or later.)

Disk Reads Alarm

This alarm is raised when the rate of disk I/O for reads on an Adaptive Server (displayed as a rate per second) goes above normal levels.

Since this metric is included in calibration, the maximum value, and thereby the alarm thresholds and flow speed, are determined by statistical sampling.

Disk reads are one indication of activity on an Adaptive Server.

Spike in disk reads can be due to several reasons:

• A simple increase in the number of clients connected to an ASE

• A batch job running against a large amount of data

• An aberrant user connected to the Adaptive Server unintentionally running a poorly structured query

Use the Devices drilldown to see if the I/O activity is evenly distributed across the disk devices.

Use the User Activity drilldown to isolate processes and users requesting a large number of I/Os.

Disk Writes Alarm

This alarm is raised when the rate if disk I/O for writes on an Adaptive Server (displayed as a rate per second) goes above normal levels.

Since this metric is included in calibration, the maximum value, and thereby the alarm thresholds and flow speed, are determined by statistical sampling.

Disk writes are one indication of activity on an Adaptive Server.

Spikes in disk writes can be due to several reasons:

• A simple increase in the number of clients connected to the ASE

• A batch job performing a large number of updates or inserts

• An aberrant user connected to the Adaptive Server running an expected transaction.

Use the Devices drilldown to see if the I/O activity is evenly distributed across the disk devices.

Use the User Activity drilldown to isolate processes performing a large number of I/O's.