ENA discovers the supported IP SLA operation types on all monitored devices. Polled attributes use the RTTMON MIB, attributes vary according to the operation type.
ENA's HTTP operation supports the HTTP GET operation. It measures the Round Trip Time (RTT) taken to connect and access data from an HTTP server. This HTTP operation involves 3 stages:
- a DNS operation measuring the DNS RTT.
- a TCP Connect operation using the domain name to connect to the appropriate HTTP server measuring the RTT for this operation.
- an HTTP Get request measuring the RTT to retrieve the specified HTML page from the HTTP server.
A total HTTP RTT is the sum of the DNS RTT, the TCP Connect RTT, and the HTTP RTT. The results of an HTTP operation are useful in monitoring your web server performance levels, by determining the RTT taken to retrieve a web page.
HTTP server response time measurements:
|DNS Time||RTT taken to perform domain name look up.|
|TCP Time||RTT taken to perform a TCP connect to the HTTP server. The TCP connect is performed after the DNS operation.|
|HTTP Time||RTT taken to send a request and receive a response from the HTTP server (the operation retrieves the base HTML page only)|
HTTP operation attributes:
|Operation Index||unique identifier of the operation.|
|Name||IP SLA operation name.|
|Type||type of operation to be performed.|
|Frequency||sets the duration between initiating each operation. You should not set this to a value that is of a shorter duration than Timeout. The minimum allowed value is 10 seconds.|
|Tag||descriptive string used by ENA to identify the operation target.|
|Owner||identifies the creator the operation.|
|Sub-Type||code that represents the specific type of RTT operation, i.e. HTTP Get.|
|Protocol||protocol used by the operation.|
|Source Address||specifies the IP address of the source.|
port on the source device used by the operation.
|TOS||defines the IP Type of Service (TOS) byte for request packets. This attribute may also be used as a Differentiated Services Code Point (DSCP).|
|Lifespan||IP SLA operation interval, by default set to forever. i.e. once created it exists forever on the device, unless deleted by ENA. You can enter a limited lifespan, by entering a value in seconds. When this time elapses, the operation and ENA has to recreate it.|
|VRF Name||name of the MPLS IP VPN VRF.|
|Timeout||length of time, in seconds, that ENA waits for a response from the IP SLA operation before marking it as timed-out. You should not set a value which is of a greater duration than Frequency.|
|HTTPVersion||HTTP Version, e.g. "1.0".|
|URL||URL to retrieve.|
|AdminCache||boolean - if true - download cache pages.|
|Proxy||URL of the proxy server.|
HTTP operation time series attributes:
|Object Name||Attribute and Description|
|rttMonLatestRttOperCompletionTime||Completion Time. The latest completion time of RTT operations that successfully complete.|
|rttMonLatestHTTPOperDNSRTT||DNS Time. Round Trip Time taken to perform DNS query within the HTTP operation.|
|rttMonLatestHTTPOperTransactionRTT||TCP Time. Round Trip Time taken to connect to the server.|
|rttMonLatestHTTPOperTCPConnectRTT||HTTP Time. Round Trip Time taken to connect to the HTTP server.|
|rttMonLatestHTTPOperMessageBodyOctets||Octets. The size of the message body received as a response to the HTTP request.|
|rttMonLatestHTTPOperSense||State. Latest completion time of any RTT operation that successfully completes.|
|rttMonLatestHTTPErrorSenseDescription||Sense. A sense description for the completion
status of the latest RTT operation.