eG Monitoring
 

Measures reported by LtmVSrvDetailsTest

A virtual server is capable of performing the following:

  • Distribute client requests across multiple servers to balance server load;

  • Apply various behavioral settings to a specific type of traffic;

  • Enable persistence for a specific type of traffic;

  • Direct traffic according to user-written iRules®

In addition, virtual servers can also be used in the following ways:

  • Directing traffic to a load balancing pool;

  • Sharing an IP address with a VLAN node;

  • Forwarding traffic to a specific destination IP address;

  • Increasing the speed of processing HTTP traffic;

  • Increasing the speed of processing Layer 4 traffic;

  • Relaying DHCP traffic

Since the virtual servers are able to manage the traffic and divert client requests to servers that are managing fewer requests, poor performance and outages can be avoided. Irregularities in load balancing can cause significant delay in request processing thus affecting the user experience with the load balancing system.To avoid this, you can configure the periodic execution of the LtmVSrvDetailsTest test.

For each virtual server configured on the traffic manager, this test continuously monitors the load on the load-balancing virtual servers and reveals how well each server processes client requests. In addition, this test detects inconsitencies in load-balancing early on and warns administrators of possible deviations proactively.

The measures made by this test are as follows:

Measurement Description Measurement Unit Interpretation
Data_transmitted Indicates the rate at which data is transmitted from this virtual server during the last measurement period. MB/Sec Compare the value of these measures across the virtual servers to identify the server that is experiencing the maximum traffic.
Data_received Indicates the rate at which data is received by this virtual server during the last measurement period. MB/Sec
Pkts_transmitted Indicates the rate at which packets were transmitted from this virtual server during the last measurement period. Packets/Sec Compare the value of these measures across the virtual servers to identify the server that is handling maximum traffic.
Pkts_received Indicates the rate at which packets were received by this virtual server during the last measurement period. Packets/Sec
Active_conns Indicates the number of connections that are currently active on this virtual server. Number This measure is a good indicator of the load on the virtual server.
Total_conns Indicates the total number of connections established on this virtual server since the restart of the traffic manager. Number  
Connection_rate Indicates the rate at which connections were established during the last measurement period. Conns/Sec  
Conns_usage Indicates the percentage of connections that were used by this virtual server. Percent A value close to 100% indicates that the virtual server is currently overloaded.
Max_conns Indicates the maximum number of connections that were established on this virtual server since the start of the traffic manager. Number  
Total_requests Indicates the rate at which the requests were processed by this virtual server. Reqs/Sec This measure is a good indicator of the workload on the virtual server.

Comparing the value of this measure across virtual servers will help you determine whether all the requests have been processed or not. Request processing bottlenecks if any, can thus be isolated and resolved.
Cpu_usage Indicates the percentage of time this virtual server was busy during the past minute. Percent A value close to 100 is a cause of concern.
Avg_conn_duration Indicates the average time required for establishing all the connections to this virtual server. Milliseconds A sudden/gradual increase in the value of this measure may indicate connection issues to the virtual server.