| Oracle® Enterprise Manager Oracle Collaboration Suite Metric Reference Manual 10g Release 2 (10.2) Part Number B25985-01 |
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View PDF |
| Oracle® Enterprise Manager Oracle Collaboration Suite Metric Reference Manual 10g Release 2 (10.2) Part Number B25985-01 |
|
|
View PDF |
The POP (Post Office Protocol) Server provides email access for Internet Standards Based mail clients. POP is intended to permit a client to access a mail drop. POP is not intended to provide extensive manipulation operations of mail on the server. Normally, mail is downloaded and then deleted from the mail drop.
This category contains metrics that provide information about AUTH commands that all clients are sending to the POP Server. A POP client uses the AUTH command to indicate an authentication mechanism to the server, perform an authentication protocol exchange, and (optionally) negotiate a protection mechanism for subsequent protocol interactions. The authentication and protection mechanisms used by the POP3 AUTH command are those used by IMAP4.
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Note: For all target versions, the collection frequency for each metric is every 10 minutes. |
The following table lists the metrics and their descriptions.
Table 18-1 AUTH Details Metrics
| Metric | Description |
|---|---|
|
AUTH Average Time (milliseconds) |
Measures the average number of milliseconds the POP Server requires to process AUTH commands. |
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AUTH Failure Rate (Failures/minute) |
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AUTH Rate (Requests/minute) |
Measures the number of AUTH commands sent to the POP Server each minute. |
This informational metric measures the number of failed AUTH commands sent to the POP Server each minute.
User Action
Root causes can include:
Mandatory password changes. Failures can increase if multiple e-mail users change their password at the same time. The problem will go away after users have changed their password. Over time, a site should expect the password policy to even out and not cause thresholds to be crossed.
Oracle directory server is temporarily unavailable. Authentications are not cached. If the Oracle directory server service is not available, people will not be able to log in.
The POP Server and the Oracle directory server cannot communicate over the network. Note this could be caused by changes in DNS, routers, or firewalls.
Insufficient connection pools for Oracle directory server lookups. Oracle Email protocol servers share connection pools for all client connections into Oracle directory server. If the authentication rate is high and the number of maximum connections into Oracle directory server is small, this could cause contention issues.
Check that the Oracle Collaboration Suite Database mail host is up and running and that the POP Server can connect to it. Also, check that the listener for Oracle Collaboration Suite Database (mailstore) is up and running.
This section contains metrics that provide information on network resources used by the POP Server. This includes the amount of data transferred to and from this server and the number of client connections to this server.
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Note: For all target versions, the collection frequency for each metric is every 10 minutes. |
The following table lists the metrics and their descriptions.
Table 18-2 Network Metrics
| Metric | Description |
|---|---|
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Client Connection Rate (Connections/minute) |
Number of new POP client sessions created per minute. |
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Current Client Connections |
Number of client sessions currently open on the POP Server. |
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Data Reception Rate (Kb/minute) |
Amount of data the POP Server is receiving per minute from POP clients. |
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Data Transmission Rate (Kb/minute) |
Amount of data sent to clients per minute by the POP Server. It includes traffic due to mail and POP responses related data. |
This category contains metrics that provide information about PASS commands received by the POP Server. When a POP client issues the PASS command, the POP Server uses the argument pair from the USER and PASS commands to determine if the client should be given access to the user's mail drop.
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Note: For all target versions, the collection frequency for each metric is every 10 minutes. |
The following table lists the metrics and their descriptions.
Table 18-3 PASS Details Metrics
| Metric | Description |
|---|---|
|
PASS Average Time (milliseconds) |
Average number of milliseconds the POP Server requires to process PASS commands |
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PASS Failure Rate (Failures/minute) |
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PASS Rate (Requests/minute) |
Number of PASS commands sent to the POP Server each minute |
This metric measures the rate of failed PASS commands (login failures) sent to the POP Server each minute. It is an aggregate value that includes login failures for bad user names or passwords, account validation failures against an Oracle directory server, or failures to access an Oracle Collaboration Suite Database (mailstore) after successful validation of the account.
To successfully process a POP PASS command, the server first communicates with the Oracle directory server to authenticate the user. A successful authentication with the Oracle directory server returns an Oracle Collaboration Suite Database (mailstore) to which the user will need a connection. If the POP Server is not able to communicate with the default mailstore, the login could return a failure.
Metric Summary
The following table shows how often the metric's value is collected and compared against the default thresholds. The Consecutive Number of Occurrences Preceding Notification column indicates the consecutive number of times the comparison against thresholds should hold TRUE before an alert is generated.
Table 18-4 Metric Summary Table
| Target Version | Evaluation and Collection Frequency | Upload Frequency | Operator | Default Warning Threshold | Default Critical Threshold | Consecutive Number of Occurrences Preceding Notification | Alert Text |
|---|---|---|---|---|---|---|---|
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All Versions |
Every 10 Minutes |
After Every Sample |
> |
300 |
500 |
1 |
The login failure rate is %value% |
User Action
An increase in login failures could be due to a problem with one of the mail systems or to a large number of invalid user account and password pairs attempting to log in. You can test for these conditions on a test account for each Oracle Collaboration Suite Database (mailstore). If you are able to log into the POP Server successfully with a test account and you still notice a large number of failures, this could indicate that someone is attempting to break into your POP Server. Perform the following checks:
Check the log files. Client IP addresses are logged in the log files when the log level is set to the Notification level or higher. Use esd_logscan.pl to scan the POP server log files.
An attack on your POP Servers will result in a load on your Oracle directory server. Check the log files for sufficient client resources to the Oracle directory server. Use esd_logscan.pl to scan the POP server log files.
If the test account fails to login, check to see if the POP Server has connectivity to the Oracle directory server and the Oracle Collaboration Suite Database (mailstore).
Check whether a process on the target is able to connect and log into the Oracle directory server.
Check that the Oracle Collaboration Suite Database (mailstore) is up and running, the listener for the Oracle Collaboration Suite Database is up and running, and the connect string is registered properly in the infrastructure Oracle directory server.
This category measures the usage of resources like databases connections and server threads. The POP Server maintains a pool of connections to database(s).
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Note: For all target versions, the collection frequency for each metric is every 10 minutes. |
The following table lists the metrics and their descriptions.
Table 18-5 Resource Usage Metrics
| Metric | Description |
|---|---|
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Database Connection Failure Rate (Failures/minute) |
This is the number of times per minute that the POP Server failed to get a database connection from the pool of database connections. This value should ideally be zero, because anytime the POP Server fails to get a connection, the end user will see an error. Database connection failures can occur if more than the allowed number of user requests come in within a short span of time. This scenario is likely after the Oracle Collaboration Suite Database (mailstore) comes back online after being offline for sometime and all the users try to reconnect to it. In this case, the pool should stabilize within a few minutes on its own. To prevent a connection overload to the Oracle Collaboration Suite Database (mailstore), increase the maximum number of connections allowed to the Oracle Collaboration Suite Database (mailstore) database if needed. |
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Database Connections In Use |
Number of database connections currently in use by the POP Server. This is not the total number of connections in the connection pool, but a subset consisting of database connections in the pool that are currently in use. A growing trend for this metric may indicate an increase in POP workload or a slowdown in database response time. Use standard database monitoring tools to resolve these problems. |
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Protocol Threads In Use |
This metric shows the number of server threads busy in the POP Server. Each busy thread represents one currently active request on a POP session. A growing trend may indicate an increase in POP workload or a slowdown in database response time. Use standard database monitoring tools to resolve these problems. |
This category contains metrics that provide information about the Up/Down status of the POP Server.
This metric provides information about the Up/Down status of the POP Server and alerts you when the status is down. The POP Server shows a status of Down when all POP processes on the target are down.
Metric Summary
The following table shows how often the metric's value is collected and compared against the default thresholds. The Consecutive Number of Occurrences Preceding Notification column indicates the consecutive number of times the comparison against thresholds should hold TRUE before an alert is generated.
Table 18-6 Metric Summary Table
| Target Version | Evaluation and Collection Frequency | Upload Frequency | Operator | Default Warning Threshold | Default Critical Threshold | Consecutive Number of Occurrences Preceding Notification | Alert Text |
|---|---|---|---|---|---|---|---|
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All Versions |
Every 5 Minutes |
After Every Sample |
= |
0 |
Not Defined |
1 |
The POP server is down |
User Action
You can start the POP Server by selecting the target and clicking the Start button on the Email Application home page in the Enterprise Manager. If the POP Server does not start, a probable cause is that the server cannot connect to at least one of the Oracle Collaboration Suite Databases (mailstores) or it cannot connect to the Oracle directory server. Check the following:
Verify that a process on the target host is able to connect to and log into the system's Oracle directory server.
Verify that the Oracle Collaboration Suite Database (mailstore) is up and running and the connect string is correctly and accurately registered in the Oracle directory server.
This category contains metrics that chart information about RETR commands received by the POP Server. A POP client issues the RETR command to retrieve a message.
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Note: For all target versions, the collection frequency for each metric is every 10 minutes. |
The following table lists the metrics and their descriptions.
Table 18-7 RETR Details Metrics
| Metric | Description |
|---|---|
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RETR Average Time (milliseconds) |
Measures the average number of milliseconds the POP Server requires to process RETR commands |
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RETR Failure Rate (Failures/minute) |
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RETR Rate (Requests/minute) |
Measures the number of RETR commands sent to the POP Server each minute |
This informational metric measures the number of failed RETR commands sent to the POP Server each minute.
User Action
RETR command failures are often a result of the POP Server not being able to connect to one or more of the mailstores. Root causes could include:
A mailstore is down. If the information store database or the listener for the information store is not running, then the POP Server will not be able to communicate with it.
Insufficient connection pool maximum for a mailstore. Oracle Email protocol servers share connection pools for all client connections to the mailstore. This leverages the resources required to get folder and message information. A large number of mail client connections will share a much smaller number of connections without contention issues. While the multiplier for connection pools will vary widely based upon how a company uses their mail system, the maximum connect pool value is typically in the 10's to support a concurrent user base in the low thousands. If there is capacity, consider adding another POP instance on this host or increasing the maximum connection pool size per POP instance.
This category contains metrics that provide information about POP Server security.
This represents the rate of new connection requests rejected by the POP Server per minute. A connection refusal occurs when a server detects that too many new connection requests are coming in a short period of time from any one IP address or there are too many concurrent connections from a given IP address. You can change the number of connections allowed or the time window in which the POP Server counts new connection requests.
Metric Summary
The following table shows how often the metric's value is collected.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 10 Minutes |
User Action
Check the POP Server log files to find out the IP address from which 'flooding' is detected. Ensure that only a reasonable number of mail clients are running on this machine. If the machine is running several mail clients for the same (or different) users, the POP Server may detect a 'flooding'. If required, either increase the number of connections allowed or decrease the amount of time in which flooding is detected to the values appropriate for your site and type of mail clients used. Use esd_logscan.pl to scan the POP server log files.
This category contains metrics that provide information about STAT commands received by the POP Server. POP clients use the STAT command to query the POP Server for the number of e-mail messages in the user's mail drop.
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Note: For all target versions, the collection frequency for each metric is every 10 minutes. |
The following table lists the metrics and their descriptions.
Table 18-8 STAT Details Metrics
| Metric | Description |
|---|---|
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STAT Average Time (milliseconds) |
Measures the average number of milliseconds the POP Server requires to process STAT commands |
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STAT Failure Rate (Failures/minute) |
Measures the number of failed STAT commands sent to the POP Server each minute |
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STAT Rate (Requests/Minute) |
Measures the number of STAT commands sent to the POP Server each minute |
This category contains metrics that provide information about TOP commands received by the POP Server. A POP client issues the TOP command to retrieve the headers and opening lines of a message.
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Note: For all target versions, the collection frequency for each metric is every 10 minutes. |
The following table lists the metrics and their descriptions.
Table 18-9 TOP Details Metrics
| Metric | Description |
|---|---|
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TOP Average Time (milliseconds) |
Measures the average number of milliseconds the POP Server required to process TOP commands |
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TOP Failure Rate (Failures/minute) |
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TOP Rate (Requests/minute) |
Measures the number of TOP commands sent to the POP Server each minute |
This informational metric measures the number of failed TOP commands sent to the POP Server each minute.
User Action
TOP command failures are often a result of the POP Server not being able to connect to one or more of the mailstores. Root causes could include:
A mailstore is down. If the information store database or the listener for the information store is not running, then the POP Server will not be able to communicate with it.
Insufficient connection pool maximum for a mailstore. Oracle Email protocol servers share connection pools for all client connections to the mailstore. This leverages the resources required to get folder and message information. A large number of mail client connections will share a much smaller number of connections without contention issues. While the multiplier for connection pools will vary widely based upon how a company uses their mail system, the maximum connect pool value is typically in the 10's to support a concurrent user base in the low thousands. If there is capacity, consider adding another POP instance on this host or increasing the maximum connection pool size per POP instance.
