Procedure 5.1. Starting Hawk¶

To use Hawk, the respective Web service must be started on the node that you want to connect to via the Web interface. For communication, the standard HTTPS protocol and port 7630 is used.

1. On the node you want to connect to, open a shell and log in as root.

2. Check the status of the service by entering

   rchawk status

3. If the service is not running, start it with

   rchawk start

   If you want Hawk to start automatically at boot time, execute the following command:

   chkconfig hawk on

1. On any machine, start a Web browser and make sure that JavaScript and cookies are enabled.

2. Point it at the IP address or hostname of any cluster node running the Hawk Web service, or the address of any IPaddr(2) resource that you may have configured:

   https://IPaddress:7630/

   Certificate Warning

   Depending on your browser and browser options, you may get a certificate warning when trying to access the URL for the first time. This is because Hawk uses a self-signed certificate that is not considered trustworthy per default. In this case, verify the certificate. To proceed anyway, you can add an exception in the browser to bypass the warning. To avoid the warning in the first place, the self-signed certificate can also be replaced with a certificate signed by an official Certificate Authority. For information on how to do so, refer to Replacing the Self-Signed Certificate.

3. On the Hawk login screen, enter the Username and Password of the hacluster user (or of any other user that is a member of the haclient group) and click Log In.

   The Cluster Status screen appears, displaying the status of your cluster nodes and resources, similar to the output of the crm_mon command.

Procedure 5.3. Using the Setup Wizard¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select Setup Wizard. The Cluster Setup Wizard shows a list of available resource sets. If you click an entry, Hawk displays a short help text about the resource set.

3. Select the resource set you want to configure and click Next.

4. Follow the instructions on the screen. If you need information about an option, click it to display a short help text in Hawk.

Procedure 5.4. Adding Primitive Resources¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select Resources. The Resources screen shows categories for all types of resources. It lists any resources that are already defined.

3. Select the Primitive category and click the plus icon.

4. Specify the resource:

   1. Enter a unique Resource ID.

   2. From the Class list, select the resource agent class you want to use for the resource: lsb, ocf, service, or stonith. For more information, see Section 4.2.2, “Supported Resource Agent Classes”.

   3. If you selected ocf as class, specify the Provider of your OCF resource agent. The OCF specification allows multiple vendors to supply the same resource agent.

   4. From the Type list, select the resource agent you want to use (for example, IPaddr or Filesystem). A short description for this resource agent is displayed.

      The selection you get in the Type list depends on the Class (and for OCF resources also on the Provider) you have chosen.

5. Hawk automatically shows any required parameters for the resource plus an empty drop-down list that you can use to specify an additional parameter.

   To define Parameters (instance attributes) for the resource:

   1. Enter values for each required parameter. A short help text is displayed as soon as you click the input field next to a parameter.

   2. To completely remove a parameter, click the minus icon next to the parameter.

   3. To add another parameter, click the empty drop-down list, select a parameter and enter a value for it.

6. Hawk automatically shows the most important resource Operations and proposes default values. If you do not modify any settings here, Hawk will add the proposed operations and their default values as soon as you confirm your changes.

   For details on how to modify, add or remove operations, refer to Procedure 5.14, “Adding or Modifying Monitor Operations”.

7. Hawk automatically lists the most important meta attributes for the resource, for example target-role.

   To modify or add Meta Attributes:

   1. To set a (different) value for an attribute, select one from the drop-down list next to the attribute or edit the value in the input field.

   2. To completely remove a meta attribute, click the minus icon next to it.

   3. To add another meta attribute, click the empty drop-down list and select an attribute. The default value for the attribute is displayed. If needed, change it as described above.

8. Click Create Resource to finish the configuration. A message at the top of the screen shows if the resource was successfully created or not.

Procedure 5.5. Adding a STONITH Resource¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select Resources. The Resources screen shows categories for all types of resources and lists all defined resources.

3. Select the Primitive category and click the plus icon.

4. Specify the resource:

   1. Enter a unique Resource ID.

   2. From the Class list, select the resource agent class stonith.

   3. From the Type list, select the STONITH plug-in for controlling your STONITH device. A short description for this plug-in is displayed.

5. Hawk automatically shows the required Parameters for the resource. Enter values for each parameter.

6. Hawk displays the most important resource Operations and proposes default values. If you do not modify any settings here, Hawk will add the proposed operations and their default values as soon as you confirm.

7. Adopt the default Meta Attributes settings if there is no reason to change them.

8. Confirm your changes to create the STONITH resource.

Procedure 5.6. Creating Resource Templates¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select Resources. The Resources screen shows categories for all types of resources plus a Template category.

3. Select the Template category and click the plus icon.

4. Enter a Template ID.

5. Specify the resource template as you would specify a primitive. Follow Procedure 5.4: Adding Primitive Resources, starting with Step 4.b.

6. Click Create Resource to finish the configuration. A message at the top of the screen shows if the resource template was successfully created.

Procedure 5.7. Referencing Resource Templates¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. To reference the newly created resource template in a primitive, follow these steps:

   1. In the left navigation bar, select Resources. The Resources screen shows categories for all types of resources. It lists all defined resources.

   2. Select the Primitive category and click the plus icon.

   3. Enter a unique Resource ID.

   4. Activate Use Template and, from the drop-down list, select the template to reference.

   5. If needed, specify further Parameters, Operations, or Meta Attributes as described in Procedure 5.4, “Adding Primitive Resources”.

3. To reference the newly created resource template in colocational or order constraints, proceed as described in Procedure 5.9, “Adding or Modifying Colocational or Order Constraints”.

Procedure 5.8. Adding or Modifying Location Constraints¶

For location constraints, specify a constraint ID, resource, score and node:

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select Constraints. The Constraints screen shows categories for all types of constraints. It lists all defined constraints.

3. To add a new Location constraint, click the plus icon in the respective category.

   To modify an existing constraint, click the wrench icon next to the constraint and select Edit Constraint.

4. Enter a unique Constraint ID. When modifying existing constraints, the ID is already defined.

5. Select the Resource for which to define the constraint. The list shows the IDs of all resources that have been configured for the cluster.

6. Set the Score for the constraint. Positive values indicate the resource can run on the Node you specify in the next step. Negative values mean it should not run on that node. Setting the score to INFINITY forces the resource to run on the node. Setting it to -INFINITY means the resources must not run on the node.

7. Select the Node for the constraint.

8. Click Create Constraint to finish the configuration. A message at the top of the screen shows if the constraint was successfully created.

Procedure 5.9. Adding or Modifying Colocational or Order Constraints¶

For both types of constraints specify a constraint ID and a score, then add resources to a dependency chain:

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select Constraints. The Constraints screen shows categories for all types of constraints and lists all defined constraints.

3. To add a new Colocation or Order constraint, click the plus icon in the respective category.

   To modify an existing constraint, click the wrench icon next to the constraint and select Edit Constraint.

4. Enter a unique Constraint ID. When modifying existing constraints, the ID is already defined.

5. Define a Score.

   For colocation constraints, the score determines the location relationship between the resources. Positive values indicate the resources should run on the same node. Negative values indicate the resources should not run on the same node. Setting the score to INFINITY forces the resources to run on the same node. Setting it to -INFINITY means the resources must not run on the same node. The score will be combined with other factors to decide where to put the resource.

   For order constraints, the constraint is mandatory if the score is greater than zero, otherwise it is only a suggestion. The default value is INFINITY.

6. For order constraints, you can usually keep the option Symmetrical enabled. This specifies that resources are stopped in reverse order.

7. To define the resources for the constraint, follow these steps:

   1. Select a resource from the list Add resource to constraint. The list shows the IDs of all resources and all resource templates configured for the cluster.

   2. To add the selected resource, click the plus icon next to the list. A new list appears beneath. Select the next resource from the list. As both colocation and order constraints define a dependency between resources, you need at least two resources.

   3. Select one of the remaining resources from the list Add resource to constraint. Click the plus icon to add the resource.

      Now you have two resources in a dependency chain.

      If you have defined an order constraint, the topmost resource will start first, then the second etc. Usually the resources will be stopped in reverse order.

      However, if you have defined a colocation constraint, the arrow icons between the resources reflect their dependency, but not their start order. As the topmost resource depends on the next resource and so on, the cluster will first decide where to put the last resource, then place the depending ones based on that decision. If the constraint cannot be satisfied, the cluster may decide not to allow the resource to run at all.

   4. Add as many resources as needed for your colocation or order constraint.

   5. If you want to swap the order of two resources, click the double arrow at the right hand side of the resources to swap the resources in the dependency chain.

8. If needed, specify further parameters for each resource, like the role (Master, Slave, Started, or Stopped).

9. Click Create Constraint to finish the configuration. A message at the top of the screen shows if the constraint was successfully created.

Procedure 5.10. Using Resource Sets for Colocation or Order Constraints¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. Define colocation or order constraints as described in Procedure 5.9, “Adding or Modifying Colocational or Order Constraints”.

3. When you have added the resources to the dependency chain, you can put them into a resource set by clicking the chain icon at the right hand side. A resource set is visualized by a frame around the resources belonging to a set.

4. You can also add multiple resources to a resource set or create multiple resource sets.

5. To extract a resource from a resource set, click the scissors icon above the respective resource.

   The resource will be removed from the set and put back into the dependency chain at its original place.

6. Confirm your changes to finish the constraint configuration.

Procedure 5.11. Removing Constraints¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select Constraints. The Constraints screen shows categories for all types of constraints and lists all defined constraints.

3. Click the wrench icon next to a constraint and select Remove Constraint.

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. Configure a location constraint for the resource as described in Procedure 5.8, “Adding or Modifying Location Constraints”.

3. Add the migration-threshold meta attribute to the resource as described in Procedure 5.4: Adding Primitive Resources, Step 7 and enter a Value for the migration-threshold. The value should be positive and less than INFINITY.

4. If you want to automatically expire the failcount for a resource, add the failure-timeout meta attribute to the resource as described in Procedure 5.4: Adding Primitive Resources, Step 7 and enter a Value for the failure-timeout.

5. If you want to specify additional failover nodes with preferences for a resource, create additional location constraints.

Procedure 5.12. Specifying Resource Stickiness¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. Add the resource-stickiness meta attribute to the resource as described in Procedure 5.4: Adding Primitive Resources, Step 7.

3. Specify a value between -INFINITY and INFINITY for the resource-stickiness.

Procedure 5.13. Setting the Placement Strategy¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select Cluster Properties to view the global cluster options and their current values.

3. From the Add new property drop-down list, choose placement-strategy.

4. Depending on your requirements, set Placement Strategy to the appropriate value.

5. Click the plus icon to add the new cluster property including its value.

6. Confirm your changes.

Procedure 5.14. Adding or Modifying Monitor Operations¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select Resources. The Resources screen shows categories for all types of resources and lists all defined resources.

3. Select the resource to modify, click the wrench icon next to it and select Edit Resource. The resource definition is displayed. Hawk automatically shows the most important resource operations (monitor, start, stop) and proposes default values.

4. To change the values for an operation:

   1. Click the pen icon next to the operation.

   2. In the dialog that opens, specify the following values:

      • Enter a timeout value in seconds. After the specified timeout period, the operation will be treated as failed. The PE will decide what to do or execute what you specified in the On Fail field of the monitor operation.

      • For monitoring operations, define the monitoring interval in seconds.

      If needed, use the empty drop-down list at the bottom of the monitor dialog to add more parameters, like On Fail (what to do if this action fails?) or Requires (what conditions need to be fulfilled before this action occurs?).

   3. Confirm your changes to close the dialog and to return to the Edit Resource screen.

5. To completely remove an operation, click the minus icon next to it.

6. To add another operation, click the empty drop-down list and select an operation. A default value for the operation is displayed. If needed, change it by clicking the pen icon.

7. Click Apply Changes to finish the configuration. A message at the top of the screen shows if the resource was successfully updated or not.

Procedure 5.15. Adding a Resource Group¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select Resources. The Resources screen shows categories for all types of resources and lists all defined resources.

3. Select the Group category and click the plus icon.

4. Enter a unique Group ID.

5. To define the group members, select one or multiple entries in the list of Available Primitives and click the < icon to add them to the Group Children list. Any new group members are added to the bottom of the list. To define the order of the group members, you currently need to add and remove them in the order you desire.

6. If needed, modify or add Meta Attributes as described in Adding Primitive Resources, Step 7.

7. Click Create Group to finish the configuration. A message at the top of the screen shows if the group was successfully created.

Procedure 5.16. Adding or Modifying Clones¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select Resources. The Resources screen shows categories for all types of resources and lists all defined resources.

3. Select the Clone category and click the plus icon.

4. Enter a unique Clone ID.

5. From the Child Resource list, select the primitive or group to use as a sub-resource for the clone.

6. If needed, modify or add Meta Attributes as described in Procedure 5.4: Adding Primitive Resources, Step 7.

7. Click Create Clone to finish the configuration. A message at the top of the screen shows if the clone was successfully created.

Procedure 5.17. Starting A New Resource¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select Cluster Status.

3. In one of the individual resource views, click the wrench icon next to the resource and select Start. To continue, confirm the message that appears. As soon as the resource has started, Hawk changes the resource's color to green and shows on which node it is running.

Procedure 5.18. Cleaning Up A Resource¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select Cluster Status.

3. In one of the individual resource views, click the wrench icon next to the failed resource and select Clean Up. To continue, confirm the message that appears.

   This executes the commands crm_resource -C and crm_failcount -D for the specified resource on the specified node.

Procedure 5.19. Removing a Cluster Resource¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select Cluster Status.

3. Clean up the resource on all nodes as described in Procedure 5.18, “Cleaning Up A Resource”.

4. In one of the individual resource views, click the wrench icon next to the resource and select Stop. To continue, confirm the message that appears.

5. Remove all constraints that relate to the resource, otherwise removing the resource will not be possible. For details, refer to Procedure 5.11, “Removing Constraints”.

6. If the resource is stopped, click the wrench icon next to it and select Delete Resource.

Procedure 5.20. Manually Migrating a Resource¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select Cluster Status.

3. In one of the individual resource views, click the wrench icon next to the resource and select Move.

4. In the new window, select the node to which to move the resource.

   This creates a location constraint with an INFINITY score for the destination node.

5. Alternatively, select to move the resource Away from current node.

   This creates a location constraint with a -INFINITY score for the current node.

6. Click OK to confirm the migration.

Procedure 5.21. Clearing a Migration Constraint¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select Cluster Status.

3. In one of the individual resource views, click the wrench icon next to the resource and select Drop Relocation Rule. To continue, confirm the message that appears.

   This uses the crm_resource -U command. The resource can move back to its original location or it may stay where it is (depending on resource stickiness).

Procedure 5.22. Changing Management Mode of Resources¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select Resources. Select the resource you want to put in unmanaged mode, click the wrench icon next to the resource and select Edit Resource.

3. Open the Meta Attributes category.

4. From the empty drop-down list, select the is-managed attribute and click the plus icon to add it.

5. Deactivate the checkbox next to is-managed to put the resource in unmanaged mode and confirm your changes.

6. After you have finished the maintenance task for that resource, reactivate the checkbox next to the is-managed attribute for that resource.

   From this point on, the resource will be managed by the High Availability Extension software again.

Procedure 5.23. Changing Maintenance Mode of Nodes¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select Cluster Status.

3. In one of the individual nodes' views, click the wrench icon next to the node and select Maintenance.

   This will add the following instance attribute to the node: maintenance="true". The resources previously running on the maintenance-mode node will become unmanaged. No new resources will be allocated to the node until it leaves the maintenance mode.

4. To deactivate the maintenance mode, click the wrench icon next to the node and select Ready.

Procedure 5.24. Viewing Recent Events of Nodes or Resources¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select Cluster Status.

3. In the Tree View or Table View, click the wrench icon next to the resource or node you are interested in and select View Recent Events.

   The dialog that opens shows the events of the last hour.

Procedure 5.25. Viewing Transitions with the History Explorer¶

The History Explorer provides transition information for a time frame that you can define. It also lists its previous runs and allows you to Delete reports that you no longer need.

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select History Explorer.

3. By default, the period to explore is set to the last 24 hours. To modify this, set another Start Time and End Time.

4. Click Display to start collecting transition data.

Procedure 5.26. Switching to Simulator Mode¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. Activate the simulator mode by clicking the wrench icon in the top-level row (next to the username), and by selecting Simulator.

   Hawk's background changes color to indicate the simulator is active. A simulator control dialog is displayed in the bottom right hand corner of the Cluster Status screen. Its title Simulator (initial state) indicates that no simulator run has occurred yet.

3. Fill the simulator's event queue:

   1. To simulate status change of a node: Click +Node in the simulator control dialog. Select the Node you want to manipulate and select its target State. Confirm your changes to add them to the queue of events listed in the controller dialog.

   2. To simulate a resource operation: Click +Op in the simulator control dialog. Select the Resource to manipulate and the Operation to simulate. If necessary, define an Interval. Select the Node on which to run the operation and the targeted Result. Confirm your changes to add them to the queue of events listed in the controller dialog.

4. Repeat the previous steps for any other node status changes or resource operations you wish to simulate.

   Figure 5.15. Hawk—Simulator with Injected Events
   
   

5. To inject other changes that you wish to simulate:

   1. Switch to one or more of the following Hawk screens: Cluster Status, Setup Wizard, Cluster Configuration, Resources, or Constraints.

      	History Explorer and Simulator Mode
      Clicking the History Explorer tab will deactivate simulator mode.

   2. Add or modify parameters on the screens as desired.

      The simulator will collect the changes from all screens and will add them to its internal queue of events.

   3. To return to the simulator control dialog, switch to the Cluster Status screen or click the wrench icon in the top-level row and click Simulator again.

6. If you want to remove an event listed in Injected State, select the respective entry and click the minus icon beneath the list.

7. Start the simulation run by clicking Run in the simulator control dialog. The Cluster Status screen displays the simulated events. For example, if you marked a node as unclean, it will now be shown offline, and all its resources will be stopped. The simulator control dialog changes to Simulator (final state).

   Figure 5.16. Hawk—Simulator in Final State
   
   

8. To view more detailed information about the simulation run:

   1. Click the Details link in the simulator dialog to see log snippets of what occurred.

   2. Click the Graph link to show the transition graph.

   3. Click CIB (in) to display the initial CIB state. To see what the CIB would look like after the transition, click CIB (out).

9. To start from scratch with a new simulation, use the Reset button.

10. To exit the simulation mode, close the simulator control dialog. The Cluster Status screen switches back to its normal color and displays the current cluster state.

Procedure 5.27. Generating a hb_report¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. Click the wrench icon next to the username in the top-level row, and select Generate hb_report.

3. By default, the period to examine is the last hour. To modify this, set another Start Time and End Time.

4. Click Generate.

5. After the report has been created, download the *.tar.bz2 file by clicking the respective link.

Procedure 5.28. Viewing Tickets with Hawk¶

Tickets are visible in Hawk if they have been granted or revoked at least once or if they are referenced in a ticket dependency—see Procedure 5.29, “Configuring Ticket Dependencies”. In case a ticket is referenced in a ticket dependency, but has not been granted to any site yet, Hawk displays it as revoked.

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select Cluster Status.

3. If the Summary View is not already active, click the respective view icon on the upper right-hand side. Along with information about cluster nodes and resources, Hawk also displays a Ticket category.

4. For more details, either click the title of the Ticket category or the individual ticket entries that are marked as links. Hawk displays the ticket's name and, in a tooltip, the last time the ticket has been granted to the current site.

   Figure 5.17. Hawk Cluster Status (Summary View)—Ticket Details
   
   

Procedure 5.29. Configuring Ticket Dependencies¶

For multi-site clusters, you can specify which resources depend on a certain ticket. Together with this special type of constraint, you can set a loss-policy that defines what should happen to the respective resources if the ticket is revoked. The attribute loss-policy can have the following values:

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. In the left navigation bar, select Constraints. The Constraints screen shows categories for all types of constraints and lists all defined constraints.

3. To add a new ticket dependency, click the plus icon in the Ticket category.

   To modify an existing constraint, click the wrench icon next to the constraint and select Edit Constraint.

4. Enter a unique Constraint ID. When modifying existing constraints, the ID is already defined.

5. Set a Loss Policy.

6. Enter the ID of the ticket that the resources should depend on.

7. Select a resource from the list Add resource to constraint. The list shows the IDs of all resources and all resource templates configured for the cluster.

8. To add the selected resource, click the plus icon next to the list. A new list appears beneath, showing the remaining resources. Add as many resources to the constraint as you would like to depend on the ticket.

   Figure 5.18. Hawk—Example Ticket Dependency¶
   
   

   Figure 5.18, “Hawk—Example Ticket Dependency” shows a constraint with the ID rsc1-req-ticketA. It defines that the resource rsc1 depends on ticketA and that the node running the resource should be fenced in case ticketA is revoked.

9. Click Create Constraint to finish the configuration. A message at the top of the screen shows if the constraint was successfully created.

Procedure 5.30. Simulating Granting and Revoking Tickets¶

1. Start a Web browser and log in to the cluster as described in Section 5.1.1, “Starting Hawk and Logging In”.

2. Click the wrench icon next to the username in the top-level row, and select Simulator.

   Hawk's background changes color to indicate the simulator is active. A simulator dialog opens in the bottom right hand corner of the screen. Its title Simulator (initial state) indicates that Cluster Status screen still reflects the current state of the cluster.

3. To simulate status change of a ticket:

   1. Click +Ticket in the simulator control dialog.

   2. Select the Action you want to simulate.

   3. Confirm your changes to add them to the queue of events listed in the controller dialog below Injected State.

4. To start the simulation, click Run in the simulator control dialog. The Cluster Status screen displays the impact of the simulated events. The simulator control dialog changes to Simulator (final state).

5. To exit the simulation mode, close the simulator control dialog. The Cluster Status screen switches back to its normal color and displays the current cluster state.