Impala Daemon Admission Controller Throughput Test

Admission control is an Impala feature that imposes limits on concurrent requests, to avoid resource usage spikes and out-of-memory conditions on busy clusters. The admission control feature lets you set an upper limit on the number of concurrent Impala requests and on the memory used by those requests. Any additional requests are queued until the earlier ones finish, rather than being cancelled or running slowly and causing contention. As other requests finish, the queued requests are allowed to proceed.

This test helps the administrators to monitor the number of requests that were queued/dequeued in the resource pool and also alerts the administrators when there are more number of requests being rejected.

Target of the test : Apache Impala

Agent deploying the test : An internal/remote agent

Outputs of the test : One set of results for the target Impala Daemon server.

Configurable parameters for the test
Parameter	Description
Test period	How often should the test be executed.
Host	The IP address of the target server that is being monitored.
Port	The port number through which the Apache Impala communicates. The default port is 25000.
Impalad URL	Each daemon server has a different endpoint URL. You need to configure the eG agent with the endpoint URL of each daemon, so that the agent can access the URL and pull metrics on the health of the target daemon servers. Specify such URL in the Impalad URL text box . To know how to configure the eG agent with the API Endpoint URLs, refer to Configuring the eG agent with the API Endpoint URLs topic in Pre-requisites for Monitoring Apache Impala.
Impalad Authorization type	To access daemon server, you need to configure Digest authorization. Digest authorization is a method used to verify the identity of a user requesting access to API Endpoint URL of the daemon server. Digest authorization uses a combination of a username, password, and a unique message digest (a type of encrypted code). Specify such Digest authorization value in the Impalad Authorization type text box considering the below criteria: If an Impalad URL is password protected (i.e., username and password configured through Cloudera Manager), then specify the value as digest_auth in the Impalad Authorization type text box. Here, digest_auth stands for Digest Authorization If an Impalad URL is not password protected, then specify the value as no_auth in the Impalad Authorization type text box. Here, no_auth stands for No Authorization. If multiple Impalad URLs are mentioned in the Impalad URL text box, then specify a comma-separated list of authorization type for each URL. For example, if there are two Impalad URLs, one URL without authorization and the other URL protected with authorization (username/password authorization), then specify Impalad Authorization type as: no_auth,digest_auth in the Impalad Authorization type text box. By default, Impalad Authorization type value is no_auth.
Impalad User, Impalad Password and Confirm Password	Once you enable web server access to the eG agent, make sure that 'password authentication' is also enabled. This is needed, so that the eG agent is able to access the built-in web server for each daemon in a safe, secure manner. Configure the credentials of such a user against Impalad User and Password text boxes. Confirm the password by retyping it in the Confirm Password text box. To know how to configure the eG agent with 'secure' access to the built-in web server, refer to Configuring the eG agent with 'secure' access to the built-in web server topic in Pre-requisites for Monitoring Apache Impala. By default, Impalad user parameter is set to none. If an Impalad URL is password protected (i.e., username and password configured through Cloudera Manager), then specify the configured username in the Impalad User text box. If an Impalad URL is not password protected, then specify the value as none in the Impalad User text box. An Impala daemon server can have multiple IP addresses. In this case, specify the corresponding URL parameter with a comma-separated list of endpoint URLs in the Impalad User textbox.
Statestored URL	Each daemon server has a different endpoint URL. You need to configure the eG agent with the endpoint URL of each daemon, so that the agent can access the URL and pull metrics on the health of the target daemon servers. Specify such URL in the Statestored URL text box . To know how to configure the eG agent with the API Endpoint URLs, refer to Configuring the eG agent with the API Endpoint URLs topic in Pre-requisites for Monitoring Apache Impala.
Statestored Authorization type	To access daemon server, you need to configure Digest authorization. Digest authorization is a method used to verify the identity of a user requesting access to API Endpoint URL of the daemon server. Digest authorization uses a combination of a username, password, and a unique message digest (a type of encrypted code). Specify such Digest authorization value in the Statestored Authorization type text box considering the below criteria: If a Statestored URL is password protected (i.e., username and password configured through Cloudera Manager), then specify the value as digest_auth in the Statestored Authorization type text box. Here, digest_auth stands for Digest Authorization If an Statestored URL is not password protected, then specify the value as no_auth in the Statestored Authorization type text box. Here, no_auth stands for No Authorization. By default, Statestored Authorization type value is no_auth.
Statestored User, Statestored Password and Confirm Password	Once you enable web server access to the eG agent, make sure that 'password authentication' is also enabled. This is needed, so that the eG agent is able to access the built-in web server for each daemon in a safe, secure manner. Configure the credentials of such a user against Statestored User and Password text boxes. Confirm the password by retyping it in the Confirm Password text box. To know how to configure the eG agent with 'secure' access to the built-in web server, refer to Configuring the eG agent with 'secure' access to the built-in web server topic in Pre-requisites for Monitoring Apache Impala. By default, Impalad user parameter is set to none. If a Statestored URL is password protected (i.e., username and password configured through Cloudera Manager), then specify the configured username in the Statestored User text box. If a Statestored URL is not password protected, then specify the value as none in the Statestored User text box.
Catalogd URL	Each daemon server has a different endpoint URL. You need to configure the eG agent with the endpoint URL of each daemon, so that the agent can access the URL and pull metrics on the health of the target daemon servers. Specify such URL in the Catalogd URL text box . To know how to configure the eG agent with the API Endpoint URLs, refer to Configuring the eG agent with the API Endpoint URLs topic in Pre-requisites for Monitoring Apache Impala.
Catalogd Authorization type	To access daemon server, you need to configure Digest authorization. Digest authorization is a method used to verify the identity of a user requesting access to API Endpoint URL of the daemon server. Digest authorization uses a combination of a username, password, and a unique message digest (a type of encrypted code). Specify such Digest authorization value in the Catalogd Authorization type text box considering the below criteria: If a Catalogd URL is password protected (i.e., username and password configured through Cloudera Manager), then specify the value as digest_auth in the Catalogd Authorization type text box. Here, digest_auth stands for Digest Authorization If an Catalogd URL is not password protected, then specify the value as no_auth in the Catalogd Authorization type text box. Here, no_auth stands for No Authorization. By default, Statestored Authorization type value is no_auth.
Catalogd User, Catalogd Password and Confirm Password	Once you enable web server access to the eG agent, make sure that 'password authentication' is also enabled. This is needed, so that the eG agent is able to access the built-in web server for each daemon in a safe, secure manner. Configure the credentials of such a user against Catalogd User and Password text boxes. Confirm the password by retyping it in the Confirm Password text box. To know how to configure the eG agent with 'secure' access to the built-in web server, refer to Configuring the eG agent with 'secure' access to the built-in web server topic in Pre-requisites for Monitoring Apache Impala. By default, Impalad user parameter is set to none. If a Catalogd URL is password protected (i.e., username and password configured through Cloudera Manager), then specify the configured username in the Catalogd User text box. If a Catalogd URL is not password protected, then specify the value as none in the Catalogd User text box.

Measurements made by the test
Measurement	Description	Measurement Unit	Interpretation
Requests admitted	Indicates the number of requests admitted in resource pool.	Number
Requests dequeued	Indicates the number of requests dequeued in resource pool.	Number
Requests queued	Indicates the number of requests queued in resource pool.	Number	A low value is required for this measure.
Requests rejected	Indicates the number of requests rejected in resource pool.	Number	Impala rejects additional requests when the queue reaches the specific limit. A low value is required for this measure.
Requests released	Indicates the number of requests released in resource pool.	Number
Requests timed-out	Indicates the number of requests timeout in resource pool.	Number	A low value is required for this measure.
Request queue time	Indicates the request queue time in resource pool.	Milliseconds	If this value increases consistently, it could indicate that the resource pool is not processing requests quickly.
Local requests queued	Indicates the number of local requests queue in resource pool.	Number
Local requests running	Indicates the number of local requests running in resource pool.	Number
Local pool memory admitted	Indicates the size of local requests admitted in resource pool.	KB
Local backend memory usage	Indicates the size of local backend memory usage in resource pool.	KB	A low value is required for this measure.
Local backend memory reserved	Indicates the size of local backend memory reserved in resource pool.	KB