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Druva Documentation

Backup and restore from CloudCache server fails

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This article applies to:

  • OS: Windows Server 2012 R2 Standard Edition (64-bit)
  • Product edition: inSync Cloud and Phoenix Cloud

Problem description

After installing the CloudCache server, it is registered with inSync Cloud and the rest of the configuration is completed.  The inSync Management Console displays the CloudCache server as connected but data fails to sync to the CloudCache server.  The cache used parameter displays 0.00 B.


CloudCache server listens on TCP port 443 by default. If a system service like IIS or SCCM is using port 443, it takes priority in connecting to the port. Hence, the CloudCache server process cannot listen to the TCP port 443 and fails to receive backup and restore requests from the inSync Client. 


 [2018-06-03 00:05:35,200] [ERROR] RPC server exited. Server instance has no attribute 'server_close' 
[2018-06-03 00:05:45,209] [INFO] Serving RPC on port 443 ... 
[2018-06-03 00:05:45,209] [ERROR] Error <class 'socket.error'>:[Errno 10013] An attempt was made to access a socket in a way forbidden by its access permissions. Traceback -Traceback (most recent call last): 
File "inSyncLib\inSyncRPCServer.pyc", line 351, in serve_forever 
File "socket.pyc", line 224, in meth 
error: [Errno 10013] An attempt was made to access a socket in a way forbidden by its access permissions 

[2018-06-03 00:04:38,167] [INFO] Unable to connect to cache server, address: (u'', 443L) [2018-06-03 00:05:30,226] [INFO] Unable to connect to cache server, address: (u'', 443L)

Output of the netstat -anob command run on cloud cache server:
Proto          Local Address            Foreign Address        State            PID
TCP                    LISTENING        4


The above traceback shows the TCP port 443 on the CloudCache server is used by the system process (PID - 4).  inSync CloudCache server will have its own process ID other than 4.  This is a clear indication that a different process is accessing the TCP port 443.

The error  -  An attempt was made to access a socket in a way forbidden by its access permissions - indicates the CloudCache server process cannot bind to port 443.


To resolve this scenario, either block the other services from listening to the TCP 443 port or change the listening TCP port of CloudCache server. The listening TCP port for CloudCache server is changed when the other services using the TCP port 443 are critical and cannot be stopped. The resolution steps are described below.

To block the other services from listening to TCP 443 port:

  1. Stop the inSync CloudCache service.
  2. Stop the other services listening to the TCP port 443. 
  3. Verify no service is listening to the TCP port 443 with the netstat -anob command. 
  4. Start the inSync CloudCache service.
  5. The command output displays as follows:

    Proto    Local Address      Foreign Address     State          PID
    TCP           LISTENING      13288


To change the listening TCP port of CloudCache server:

  1. Decommission the CloudCache server from the inSync Management Console. This may take several minutes as it is processed on the next sync cycle.
  2. After the decommissioning is complete, stop the inSync CloudCache service.
  3. Rename the inSyncCacheServer folder as inSyncCacheServer.old located on the root of C Drive.
  4. Start the inSync Cloud Cache service so that the new inSyncCacheServer folder gets created.
  5. Stop inSync CloudCache service again.
  6. In the inSyncCacheServer.cfg file, change the port number assigned to the SYNC_PORT parameter.  The CloudCache server will listen to the new port assigned in this step.
  7. Start the inSync CloudCache service again.
  8. Register the inSync CloudCache server on the Cloud with a different name than the one assigned to the server before it was decommissioned.


  1. The output of netstat -anob command must look like:

    Proto     Local Address       Foreign Address        State          PID
    TCP              LISTENING      13288

    Note that the PID number is replaced by the application PID and the new listening TCP port is 4433. 
  2. Verify the new listening port from inSyncCacheServer.log.

    [2018-07-12 17:52:18,500] [INFO] Loaded stores: {}
    [2018-07-12 17:52:18,828] [INFO] Authenticated and handed over.
    [2018-07-12 17:52:18,828] [INFO] Serving RPC on port 4433 ...
    [2018-07-12 17:52:18,828] [INFO] Client CacheServer Thread serving on ('', 4433)