[
https://issues.apache.org/jira/browse/CLOUDSTACK-816?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13740636#comment-13740636
]
Jessica Tomechak commented on CLOUDSTACK-816:
---------------------------------------------
Abhinav,
Here is the doc:
Health Checks for Load Balancer Rules
(NetScaler load balancer only)
Health checks are used in load-balanced applications to ensure that requests
are forwarded only to running, available services. When creating a load
balancer rule, you can specify a health check policy. This is in addition to
specifying the stickiness policy, algorithm, and other load balancer rule
options. You can configure one health check policy per load balancer rule.
Any load balancer rule defined on a NetScaler load balancer in CloudStack can
have a health check policy. The policy consists of a ping path, thresholds to
define "healthy" and "unhealthy" states, health check frequency, and timeout
wait interval.
When a health check policy is in effect, the load balancer will stop forwarding
requests to any resources that are found to be unhealthy. If the resource later
becomes available again, the periodic health check will discover it, and the
resource will once again be added to the pool of resources that can receive
requests from the load balancer.
You can delete or modify existing health check policies.
To configure how often the health check is performed by default, use the global
configuration setting lbrule_health check_time_interval. You can override this
value for an individual health check policy.
For details on how to set a health check policy using the UI, see Adding a Load
Balancer Rule. *** SEE STEP 7 BELOW ***
Adding a Load Balancer Rule
1. Log in to the CloudStack UI as an administrator or end user.
2. In the left navigation, choose Network.
3. Click the name of the network where you want to load balance the traffic.
4. Click View IP Addresses.
5. Click the IP address for which you want to create the rule, then click the
Configuration tab.
6. In the Load Balancing node of the diagram, click View All.
In a Basic zone, you can also create a load balancing rule without acquiring or
selecting an IP address. CloudStack internally assign an IP when you create the
load balancing rule, which is listed in the IP Addresses page when the rule is
created. To do that, select the name of the network, then click Add Load
Balancer tab. Continue with Step 7.
7. Fill in the following:
Name: A name for the load balancer rule.
Public Port: The port receiving incoming traffic to be balanced.
Private Port: The port that the VMs will use to receive the traffic.
Algorithm: Choose the load balancing algorithm you want CloudStack to use.
CloudStack supports a variety of well-known algorithms. If you are not familiar
with these choices, you will find plenty of information about them on the
Internet.
Stickiness: (Optional) Click Configure and choose the algorithm for the
stickiness policy. See Sticky Session Policies for Load Balancer Rules.
AutoScale: Click Configure and complete the AutoScale configuration as
explained in Configuring AutoScale.
*** NEW DOC BEGINS HERE ***
Health Check: (Optional; NetScaler load balancers only) Click Configure and
fill in the characteristics of the health check policy. See Health Checks for
Load Balancer Rules.
* Ping path (Optional): Sequence of destinations to which to send health check
queries. Default: / (all).
* Response time (Optional): How long to wait for a response from the health
check (2 - 60 seconds). Default: 5 seconds.
* Interval time (Optional): Amount of time between health checks (1 second - 5
minutes). Default value is set in the global configuration parameter
lbrule_health check_time_interval.
* Healthy threshold (Optional): Number of consecutive health check successes
that are required before declaring an instance healthy. Default: 2.
* Unhealthy threshold (Optional): Number of consecutive health check failures
that are required before declaring an instance unhealthy. Default: 10.
*** NEW DOC ENDS HERE ***
8. Click Add VMs, then select two or more VMs that will divide the load of
incoming traffic, and click Apply.
The new load balancer rule appears in the list. You can repeat these steps to
add more load balancer rules for this IP address.
> Document health monitoring for load balanced instances
> ------------------------------------------------------
>
> Key: CLOUDSTACK-816
> URL: https://issues.apache.org/jira/browse/CLOUDSTACK-816
> Project: CloudStack
> Issue Type: Sub-task
> Security Level: Public(Anyone can view this level - this is the
> default.)
> Components: Doc
> Reporter: Radhika Nair
> Assignee: Abhinav Roy
> Fix For: 4.2.0
>
>
> Document health monitoring for load balanced instances
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
