Troubleshooting Collaborative Editing

Collaborative editing is powered by Synchrony which synchronizes data in real time. Under normal circumstances it should not need to be managed manually by an administrator.

This page will help you troubleshoot problems with Synchrony in your instance. 

Troubleshooting collaborative editing problems

First steps

Check Synchrony is running

To check if Synchrony is running, go to  Administration  > General Configuration  >  Collaborative editing

Note: if you're running Confluence Data Center, this page will only be able to tell you if the current Confluence node is connected to your Synchrony cluster. You may want to use a third party monitoring tool to help you monitor your Synchrony cluster.  See How to check the status of Synchrony for Confluence Data Center for more info. 

Check you can edit a page

If you see an error when you edit a page, but Synchrony is running, something is preventing your browser from connecting to Synchrony. 

The most common issue is a misconfigured reverse proxy. See our proxy troubleshooting tips later in this page or head to Administering Collaborative Editing to find out more about possible proxy and SSL configurations.  

On this page:

Related pages:

Check the logs

You can find the Confluence application logs at <home-directory>/logs/atlassian-confluence.log and Synchrony specific logs at   <home-directory>/logs/atlassian-synchrony.log .

Restart Synchrony

If Synchrony is managed by Confluence, go to Administration  > General Configuration > Collaborative editing and choose Restart Synchrony.  

If you run your own standalone Synchrony cluster, manually restart Synchrony on each node. 

Check port 8091 is available

Synchrony runs on port 8091 by default. If this port is already in use by another application on your server you can use the the synchrony.port system property to change it to an available port.  

(If you're using Confluence 6.0.3 or earlier you'll need to use reza.port instead of synchrony.port.)

See Configuring System Properties to find out how to change this. 

For Confluence Data Center the way you run Synchrony is a little different. See Configuring Synchrony for more information.

Reverse proxy issues

If you have configured your reverse proxy, but can't edit pages, here's some things to check in your configuration:

  • Go to installation-directory>/conf/server.xml  and check the Connector directive. Make sure that you have correct values for <protocol> and <proxyName>. See the examples in the guides below for more information.  
  • The http connector always needs to be present in the <installation-directory>/conf/server.xml file, even if you're configuring SSL or using the AJP connector. The Synchrony health check uses HTTP and will fail if this connector is not present. Alternatively, if you do not want to include the http connector, you can use the synchrony.proxy.healthcheck.disabled system property to disable the health check. 
  • If you're using Apache, make sure you're using Apache 2.4 (with WebSockets support) and all required modules have been enabled (mod-proxymod_rewriteproxy_wstunnel).
  • If you're using Apache and want to connect directly to Synchrony, in your proxy config file, make sure you've included /synchrony and that the order of the Confluence and Synchrony directives and location blocks is correct. See the examples in the guides below for more information. 

See Administering Collaborative Editing to find out more about possible proxy and SSL configurations then check out the following guides for more information on how to include Synchrony in your reverse proxy config, if you want to connect direct to Synchrony:

Forward proxy issues

If you're using a forward or outbound proxy, you will need to add the IP that Synchrony listens on to your config to ensure it is bypassed. See Configuring Web Proxy Support for Confluence for more info.

By default, the IP is, or it will be the value of the system property, if you've customized the hostname or IP that Confluence uses to connect to Synchrony. 

Websocket issues

Collaborative editing works best with a WebSocket connection. If one can't be established due to a timeout, or a proxy server or firewall that doesn't allow WebSocket connections, the editor will attempt to connect via an XML HTTP Request (XHR).

You can use to perform a quick HTML5 WebSocket test against an echo server.

It's possible to verify the websocket connection using the developer tools in your browser. In the following example, we'll use Chrome to check the websocket connection:

  1. Open the Chrome Developer Tools (Shift + CTRL + J)
  2. Select the Network tab
  3. Select the WS filter to show only WebSocket traffic
  4. Edit a Confluence page
  5. Select the websocket connection: ws://<confluence-url>/synchrony-proxy/v1/bayeux-sync1
  6. Select the Frames/Messages tab to see the traffic between browser and the WebSocket.

SSL issues

Synchrony cannot accept direct HTTPS connections, so you will need to terminate SSL at your reverse proxy or load balancer, or at Tomcat if you are not using a reverse proxy.

Memory issues

If you experience out of memory errors related to Synchrony, you can change the heap size allocated to Synchrony using the synchrony.memory.max system property.

If you're Confluence 6.0.3 or earlier you'll need to use reza.memory.max instead of synchrony.memory.max.

See Configuring System Properties to find out how to change this.  

For Confluence Data Center the way you run Synchrony is a little different. See Configuring Synchrony for more information.

Multiple Synchrony processes

If you see an error immediatley in the editor, but Confluence reports that Synchrony is running, check to make sure that you only have one Synchrony process running. 

If you do have multiple Synchrony processes running, stop Confluence, kill the additional Synchrony processes and then restart Confluence.

You can avoid this problem by always using / stop-confluence.bat to stop Confluence, rather than simply closing the Tomcat window. 

Mixed Synchrony modes in cluster

If you're running Confluence in a cluster, all of your Confluence nodes must connect to Synchrony in the same way.

If users are able to use collaborative editing on one Confluence node, but not on another Confluence node, go to Administration  > General Configuration > Clustering, then on each node choose Collaborative editing

Make sure all of your Confluence nodes are reporting the same Synchrony mode - either Managed by Confluence, or Standalone Synchrony cluster. 

You can access all nodes in this way, you don't need to hit a specific node in your browser.

Incompatible browser extensions

Some third party browser extensions that interact with the editor, such as Grammarly, may not function correctly with collaborative editing. See (Archived) Confluence Collaborative Editing blocks Grammarly Extension to find out how to disable Grammarly for just your Confluence site.

Firewall or anti-virus interference

We've had a few reports of firewalls or anti-virus software blocking some requests to the server, resulting in unexpected behavior in the editor. You may need to add Confluence to your whitelist / trusted URLs if you experience issues. See Weird Page or Editor Behaviors with Kaspersky Internet Security for more information.

Too many people in the editor

A maximum of 12 people can edit a page at the same time. This means that people can't enter the editor if there are already 12 other people editing the page, and will need to wait until someone leaves.  

Administrators can increase or decrease this limit using a the confluence.collab.edit.user.limit system property

Create feedback reports to troubleshoot content problems

If you experience problems such as data duplication, our support team may ask you to create a feedback report to help us troubleshoot the problem. 

What data does the report include and where is it stored?

When someone creates a feedback report, we collect all the changes that have happened to that page or blog post, including the history, any page events, and Synchrony data from the editor (for the past 72 hours). This helps us construct a complete snapshot of the lifecycle of the page.

(warning) Note: Synchrony captures every key stroke made in the editor when editing a page. For example if you type "The best ice cream is Vanilla" and then backspace and change it to "Chocolate", both "Vanilla" and "Chocolate" will be included in the Synchrony data. 

The user reporting the problem will also be prompted to describe the issue in their own words. 

This data is exported as a zip file, and saved to the following directory:

  • <shared-home>/collab-data/ if you run Confluence in a cluster

  • <local-home>/shared-home/collab-data/ you are using non-clustered Confluence.

Because the collected data includes user generated content, generated reports are only kept for 5 days, then automatically deleted by the Clean up collaborative editing feedback reports scheduled job.  A maximum of 200 reports are kept at any one time.  You can change both of these values using a system property. See Recognized System Properties.  

Allow users to self report problems

By default, only people with system administrator or Confluence administrator global permissions can create a feedback report report problems through the administrative interface. You can choose to allow any user with Add page space permission to create a report.

To allow users to self-report problems:

  1. Go to Administration  > General ConfigurationCollaborative editing feedback.
  2. Under Who can create feedback reports, select the Anyone with edit permissions radio button. 

This will add the Report editing problems item to the help menu in the header, when viewing or editing a page. 

Report an editing problem

To report an editing problem from a page or blog post:

  1. Navigate to the problematic page or blog post.
  2. Select  Help > Report editing problems from the header.
  3. Enter any relevant information, such as what you were doing when the problem occurred.
  4. Select Send feedback. 

The report will be saved to the shared home directory, and will appear in the list of available reports (only accessible to system administrators). 

Report an editing problem by page ID

System administrators can also generate reports for problematic pages using the page ID. This is useful if you don't want to allow users to self-report problems.

To generate a report for a particular page or blog post:

  1. Go to Administration  > General Configuration> Collaborative editing feedback.
  2. Enter the page or blogpost ID in the
  3. Select Create report button. 

The report file will appear in the list of available reports. 

Send a report to Atlassian support

If you choose to share this data with our Support team for analysis, you can transfer the files through a support ticket.

Feedback reports should ONLY be provided when requested by a Support team member. Don't share this data in any public locations, such as in Atlassian bug reports. 

Last modified on Feb 8, 2024

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