EC2 - Instance Connectivity Test

Sometimes, an instance could be in a powered-on state, but the failure of the operating system or any fatal error in internal operations of the instance could have rendered the instance inaccessible to users. In order to enable you to promptly detect such ‘hidden’ anomalies, this test periodically runs a connectivity check on each instance available for the configured AWS user account in the monitored region, and reports whether the instances are accessible over the network or not.

Target of the test: Amazon Region

Agent deploying the test: A remote agent

Output of the test: One set of results for each instance available for the configured AWS user account in the monitored region

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.
AWS Access Key, AWS Secret Key, Confirm AWS Access Key, Confirm AWS Secret Key	To monitor an Amazon instance, the eG agent has to be configured with the access key and secret key of a user with a valid AWS account. For this purpose, we recommend that you create a special user on the AWS cloud, obtain the access and secret keys of this user, and configure this test with these keys. The procedure for this has been detailed in the Obtaining an Access key and Secret key topic. Make sure you reconfirm the access and secret keys you provide here by retyping it in the corresponding Confirm text boxes.
Proxy Host and Proxy Port	In some environments, all communication with the AWS cloud and its regions could be routed through a proxy server. In such environments, you should make sure that the eG agent connects to the cloud via the proxy server and collects metrics. To enable metrics collection via a proxy, specify the IP address of the proxy server and the port at which the server listens against the Proxy Host and Proxy Port parameters. By default, these parameters are set to none , indicating that the eG agent is not configured to communicate via a proxy, by default.
Proxy User Name, Proxy Password, and Confirm Password	If the proxy server requires authentication, then, specify a valid proxy user name and password in the proxy user name and proxy password parameters, respectively. Then, confirm the password by retyping it in the CONFIRM PASSWORD text box. By default, these parameters are set to none, indicating that the proxy sever does not require authentication by default.
Proxy Domain and Proxy Workstation	If a Windows NTLM proxy is to be configured for use, then additionally, you will have to configure the Windows domain name and the Windows workstation name required for the same against the proxy domain and proxy workstation parameters. If the environment does not support a Windows NTLM proxy, set these parameters to none.
Cloudwatch Enabled	This parameter only applies to the -Aggregated Resource Usage test. This test reports critical metrics pertaining to the resource usage of the server instances launched in the cloud. If you want this test to report resource usage metrics very frequently - say, once every minute or lesser - you will have to configure the tests to use the AWS CloudWatch service. This is a paid web service that enables you to monitor, manage, and publish various metrics, as well as configure alarm actions based on data from metrics. To enable is test to use this service, set the CloudWatch Enabled flag to Yes. On the other hand, to report resource usage metrics less frequently - say, once in 5 minutes or more - this test does not require the AWS CloudWatch service; in this case therefore, set the cloudwatch enabled flag to No. Note that for enabling CloudWatch, you will have to pay CloudWatch fees. For the fee details, refer to the AWS web site.
Exclude Instance	This parameter applies only to AWS- Instance Connectivity, AWS- Instance Resources , and AWS- Instance Uptime tests. In the Exclude Instance text box, provide a comma-separated list of instance names or instance name patterns that you do not wish to monitor. For example: i-b0c3e,7dbe56d. By default, this parameter is set to none.

Measures reported by the test:

Measurement	Description	Measurement Unit	Interpretation
Avg network delay:	Indicates the average delay between transmission of packets to this instance and receipt of the response to the packet at the source.	Secs	An increase in network latency could result from misconfiguration of the router(s) along the path, network congestion, retransmissions at the network, etc.
Min network delay:	The minimum time between transmission of a packet and receipt of the response back.	Secs	A significant increase in the minimum round-trip time is often a sure sign of network congestion.
Packet loss:	Indicates the percentage of packets lost during transmission from source to target and back.	Percent	Packet loss is often caused by network buffer overflows at a network router or by packet corruptions over the network. The detailed diagnosis for this measure provides a listing of routers that are on the path from the external agent to target server, and the delays on each hop. This information can be used to diagnose the hop(s) that could be causing excessive packet loss/delays.
Network availability of Instance:	Indicates whether the network connection to this instance is available or not.	Percent	A value of 100 indicates that the instance is accessible over the network. The value 0 indicates that the instance is inaccessible. Typically, the value 100 corresponds to a Packet loss of 0.