Long delays when establishing RMI connection after losing network connectivity
On Windows operating systems, if you are using the remote method invocation (RMI) port to connect to your WebSphere® Application Server, you might experience long delays to establish a connection to the server after you lose network connectivity. This can occur even if the server is local and the network connectivity is lost only temporarily, which is common in a wireless network environment. If you know that the server is started, but the status in the Servers views displays Stopped or Started, try to see if you can establish a connection to the server by switching the server connection from RMI to SOAP. The status of the server changes to Started.
- The easiest and safest option, is to switch your connection to use the SOAP port. SOAP connections that lose network connectivity can recover more quicker compared to an RMI connection.
- If you must use an RMI connection, you can try to modify the default
settings that pertain to the Domain Name System (DNS) caching on the Windows operating system. For
details, refer to the following Microsoft support
article. http://support.microsoft.com/kb/318803
Windows operating system has a built-in DNS caching that maintains resolved host names. Built-in DNS caching allows for faster DNS lookups. However, there is a disadvantage to having faster DNS lookups, which is if a DNS lookup fails. The Windows operating system caches the failed value, for a default time of 300 seconds. So even if the DNS server can resolve the lookup shortly thereafter, it does not actually attempt the lookup until the cache time expires. As a result, a failed DNS lookup with default settings can take as many as 5 minutes before a lookup is attempted again. Setting the cache time to 0 seconds forces the Windows operating system to never cache failed DNS lookup queries, and allow the reconnection to occur as soon as the DNS becomes available.
In the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Dnscache\Parameters
- For Windows XP or 2003:
"MaxNegativeCacheTtl"=dword:00000000
- For Windows 2000:
"NegativeCacheTime"=dword:00000000