| Measurement |
Description |
Measurement Unit |
Interpretation |
| Availability |
Whether the cluster node is responding to requests. |
Percent |
The availability is 100% when a cluster node is responding to a request and 0% when it is not. Availability problems may be caused by a misconfiguration/malfunctioning of the node, or because the node is using an invalid user account. Besides the above, this measure will report that the server is unavailable even if a connection to the node is unavailable, or if a query to the node fails. In this case, you can check the values of the DB connection availability and QryProAvailable measures to know what is exactly causing the node to not respond to requests - is it owing to a connection unavailability? or is it due to a query failure? |
| ResponseTime |
The time taken by this node to respond to a user query. This is the sum total of the connection time and query execution time. |
Secs |
A sudden increase in response time is indicative of a bottleneck at the node. This could even be owing to a connection delay and/or long running queries to the node. Whenever the value of this measure is high, it would be good practice to compare the values of the DbConnTime and QryExeTime measures for a node to zero-in on the root-cause of the poor responsiveness of the server - is it because of connectivity issues? or is it because of inefficient queries? |
| KbytesSentRate |
The rate of data being transmitted by this node in response to client requests. |
KB/Sec |
The data transmission rate reflects the workload on the server. |
| KbytesRecvdRate |
The rate of data received by this node from clients over SQL*Net. |
KB/Sec |
This measure also characterizes the workload on a node. As the data rate to a node increases, consider tuning the Service Layer Data Buffer (SDU) and the Transport Layer Data Buffer (BDU) in the TNSNames.ora and Listener.ora files to optimize packet transfers across the network. |
| DbConnAvailable |
Indicates whether the database connection to this node is available or not. |
Percent |
If this measure reports the value 100, it indicates that the database connection is available. The value 0 on the other hand indicates that the database connection is unavailable. A connection to the database may be unavailable if the database is down or if the database is listening on a port other than the one configured for it in the eG manager or owing to a poor network link. If the Availability measure reports the value 0, then, you can check the value of this measure to determine whether/not it is due to the unavailability of a connection to the server. |
| DbConnTime |
Indicates the time taken to connect to the cluster node. |
Secs |
A high value could indicate a connection bottleneck. Whenever the ResponseTime of the measure soars, you may want to check the value of this measure to determine whether a connection latency is causing the poor responsiveness of the node. |
| QryProAvailable |
Indicates whether the query to this node is executed successfully or not. |
Percent |
If this measure reports the value 100, it indicates that the query executed successfully. The value 0 on the other hand indicates that the query failed. In the event that the Availability measure reports the value 0, check the value of this measure to figure out whether the failed query is the reason why that measure reported a node unavailability. |
| QryExeTime |
Indicates the time taken for query execution. |
Secs |
A high value could indicate that one/more queries to the node are taking too long to execute. Inefficient/badly designed queries to the database often take too long to execute. If the value of this measure is higher than that of the DbConnTime measure, you can be rest assured that long running queries are causing the node to respond slowly to requests. |
| OracleNoOfRecords |
Indicates the number of records fetched from the database. |
Number |
The value 0 indicates that no records are fetched from the database. |