We were trying to tune the Sun JVM Garbage Collector of our WebLogic Server v. 10.3.2 when the server stopped for over one hour. It was lunch time so we did not kill the process. After 4012 seconds it came back. For your information, the server was a development instance with a 512 MB JVM on Solaris 9.

Here is the log message (wrapped for readability):

2012-01-10T12:48:31.227+0100: 
    10361.371: [GC[YG occupancy: 23095 K (29504 K)]
    10361.371: [Rescan (parallel) , 4012.3452758 secs]
    14373.717: [weak refs processing, 0.0006401 secs]
    14373.717: [class unloading, 0.0815919 secs]
    14373.799: [scrub symbol & string tables, 0.1392282 secs] 
    [1 CMS-remark: 416411K(491520K)] 439506K(521024K), 4012.6147003 secs] 
    [Times: user=3959.56 sys=5.79, real=4012.61 secs] 

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