Starting and Stopping Channels

Introduction

The easiest way to start and stop Channels is using the Dashboard. You can also stop individual Channels from the channel properties screen.

Note: To start/stop channels you must be a member of a role that has Start/Stop Permissions for a channel group to which the channel belongs. If you do not have permissions the the Start and Stop buttons will be disabled.

See Roles for more information.

Starting and Stopping a Single Channel [top]

The easiest way to start and stop channels is from the Dashboard:

To start a channel, click its Start button. If the channel is successfully started, its status square changes to green.

If the channel is starting up, its status square is yellow:

Tip: The status square is also yellow if the source or destination is a plugin and the plugin has not yet been started.

See From Plugin (legacy) and To Plugin (legacy) for information on how to create a channel with a plugin as the source component or destination component.

If a channel is running, click its Stop button to stop it. When the channel is stopped, its status square changes to white:

If an error occurs while a channel is running or starting, its status square becomes red:

In this case, the Errors column lists a count of the number of errors detected. Click on this count to display log information about the error that has occurred:

For more information on log information in Iguana, see Iguana Logs.

You can also stop and start a channel from its properties page:

Starting and Stopping Multiple Channels [top]

If you are a member of a role that has Start/Stop permissions, you can use the Dashboard to start and stop multiple channels at once. You can also clear errors in multiple channels.

To start multiple channels at once:

  1. For each channel that you want to start, select the check box to the left of the Start button:
  2. Or, you can select the check box in the heading row to select all of the channels on the Dashboard:
  3. When you have selected the channels, select Start Channel(s) from the Channel Actions list box to start the channels. (The Channel Actions list box is located at the bottom left of the Dashboard.)
  4. While the channels are being started, Iguana displays a status indicator at the bottom left of the Dashboard, next to the Channel Actions list box, which keeps track of how many channels remain to be updated:

To stop multiple channels:

  1. Select the check boxes of the channels that you want to stop or clear errors from.
  2. From the Channel Actions list box, select Stop Channel(s) to stop the channels. As shown above, a status indicator at the lower left of the dashboard notifies you when the update is complete.

Note: If you are not a member of any role that has Start/Stop permissions for the channel group to which a channel belongs, the check box at the left of the column and the Stop and Start buttons are disabled for that channel.

If you are a member of a role that has Edit permissions for the channel group but does not have Start/Stop permissions, the check box at the left of the column will be enabled, but you still will not be able to start or stop the channel. Iguana will display a warning dialog box if you attempt to start or stop a channel for which Start/Stop permission has not been granted.

See Roles for more information on how roles and channel group permissions are defined in Iguana.

Forcing an Iguana Channel to Stop [top]

This feature was added in version 6.1 of Iguana.

Sometimes when stopping a channel it will get stuck in a waiting state and never stops — when this occurs you can force the channel to close. The channel can then be restarted immediately.

When a stopping channel gets stuck in the “yellow light” (waiting) state — a red Force Stop button will appear in the Channel Properties. You can use this button to force the channel to stop immediately. Forcing a channel to stop causes Iguana to abandon all threads of execution for the affected channel.

The “yellow light” (waiting) state means that Iguana is waiting for a response before it can close the channel. The ideal solution would be to wait for the response and allow the channel to shut down cleanly. Unfortunately there are some cases where there is no timely response — in these cases you should use the force stop option.

There are many possible causes for this type of issue, for example: Waiting for a blocking database operation, or perhaps some type of race condition, basically anything that prevents (or slows down) a response. We have found that many “stuck” DB or HTTP operations are the result of misconfigured external systems. It’s always preferable to fix those misconfigurations, rather than using force stop routinely. However the ability to force a channel to stop greatly reduces the impact of these issues.

There is one situation where using force stop may be your best option: If you are connecting to a “badly behaved” application and fixing the issue is difficult or impossible. In this case you can use force stop whenever the problem occurs. However be aware that using Force Stop frequently will cause Iguana to gradually start using more memory (because memory used by abandoned threads is usually not recovered until the Iguana Server is restarted). Therefore if you do need to use Force Stop regularly you should restart your Iguana Server periodically during off-peak hours.

This is is how Force Stop works:

  1. From the Dashboard click on the channel name link to go to the Channel Properties:
  2. Click on the Stop Channel button.
  3. The Force Stop button will appear below Stop Channel:
  4. Click on Force Stop to stop the channel.

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