Tibero Tablespaces Test

This test tracks both the disk space usage per tablespace, as well as the rates at which data is written to and read from a tablespace.

Target of the test : A Tibero Database server

Agent deploying the test :An internal agent

Outputs of the test : One set of results for each tablespace on the target Tibero Database server being monitored.

Configurable parameters for the test
Parameter Description

Test Period

How often should the test be executed.

Host

The host for which the test is to be configured.

Port

The port to which the specified host listens. By default, the port number is 8629.

User and Password

In order to monitor a Tibero database server, a special database user account has to be created in every Tibero database instance that requires monitoring. A Click here hyperlink is available in the test configuration page, using which a new Tibero database user can be created. Alternatively, you can manually create the special database user. When doing so, ensure that this user is vested with the select any dictionary and create session privileges.

The sample script we recommend for user creation for eG monitoring is:

create user tibeg identified by tibeg default tablespace <users> temporary tablespace<temp>;

grant create session, select any dictionary tibeg;

The name of this user has to be specified in the User text box, and the password of this user has to be entered in the Password text box. This login information is required to query Tibero's internal dynamic views, so as to fetch the current status / health of the various database components.

Confirm Password

Confirm the Password by retyping it here.

Tibero SID

Specify the SID of the target Tibero database instance that is to be monitored in this text box.

Measurements made by the test
Measurement Description Measurement Unit Interpretation

Current usage

Indicates the current actual usage with respect to the current allocated size (Current size).

Percent

As a rule of thumb, at any time, about 20% of the space allocated to a tablespace should be available. In case of auto-extensible tablespaces, even if this percentage touches 100%, there would be no cause for concern. However, if a tablespace is not auto-extensible, then when the percentage disk space usage reaches 100%, all statements that attempt to acquire new space in the tablespace will fail. Under such circumstances, the underlying datafiles of the tablespace may need to be resized or reorganized. Alternately, additional datafiles could be mapped to the tablespace.

Physical reads

Indicates the rate of physical reads happening on a tablespace.

Reads/Sec

A sudden increase in the rate of data accesses may indicate a change in application characteristics. At any stage, if more than 50% of the total reads for a database instance happen to be on a particular tablespace, this may result in performance degradation.

Physical writes

Indicates the rate of physical writes happening on a tablespace.

Writes/Sec

More than 50% of the total writes for a database instance happening on a particular tablespace may be indicative of a problem scenario that needs further investigation.

Auto extensible

Indicates whether the tablespace has the capability to grow automatically or not.

 

If the tablespace is auto-extensible, then this measure will report the value Yes. If it is not extensible, then the value of this measure will be No.

The numeric values that correspond to the measure values discussed above are as follows:

Measure Value Numeric Value
No 0
Yes 1

Note:

By default, the measure reports the Measure Values listed in the table above to indicate whether/not a tablespace is auto-extensible. In the graph of this measure however, the same is represented using the numeric equivalents only.

Max size

Indicates the maximum extent (in MB) upto which a tablespace can grow.

MB

 

Current size

Indicates the current allocated size of the tablespace.

MB

If a tablespace is not auto-extensible, then its Current size will be equal to the Max size. For auto-extensible tablespaces though, the values of the Current size and Max size measures could be different.

Free space

Indicates the amount of unused space in the tablespace.

MB

The value of this measure is computed using the formula:

Max size - Current actual usage, where Current actual usage is arrived at by applying the Current usage percentage on the Current size (current allocated size) measure. For example, assume that the Max size of a tablespace is 2500 MB and its Current size is 1000 MB. Also, note that nearly 30% of the Current size has already been utilized. Therefore, the Current actual usage of the tablespace will be 30% of 1000MB, which is 300 MB. The available Free space will hence be, 2500-300, i.e. 2200 MB.

If this value is very low, then it indicates over-utilization of the tablespace.

Percent free space

Indicates the space available for overall growth expressed as a ratio of Free space with respect to the Max size of the tablespace. The formula used is: Free space/Max size*100

Percent

If this value is very low, then it indicates over-utilization of the tablespace.

Biggest extent

Indicates the size of the biggest extent in the tablespace.

MB

From both these values, you can figure out how space allocation, fragmentation, etc. have been performed on the tablespace.

Smallest extent

Indicates the size of the smallest extent in the tablespace.

MB

Remaining extents

Indicates the number of extents that can be added to a tablespace.

Number

If this value is low and the tablespace is not auto-extensible, then it indicates that the tablespace requires resizing. In the case of auto-extensible tablespaces, this phenomenon is not a cause for concern. This measure is not applicable to tablespaces that have dictionary based extent management and allocation type is user.