Oracle support note for Leap Second Hang problem that may result into 100% CPU utilization in Linux environment
- by Anand Akela
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On
or around July 1, 2012, Oracle has become aware of an issue on Linux
distributions resulting from the introduction of the leap second; this is
causing problems for some customers. Leap seconds may be introduced at
the end of June or December in a calendar year, like 2012, as necessary to
maintain time standards. Servers hosting Oracle products which are clients of
an NTP server (Network Time Protocol) may be particularly susceptible to this
issue as the NTP server is updated.
Linux
distributions which may be affected include Oracle Enterprise Linux, Red Hat
Enterprise Linux, Oracle VM and Oracle Unbreakable Enterprise Kernel. Asianux 2
and 3, based on RHEL 4 and 5, may also be affected. One report of correction to
high agent CPU using Note
1472421.1 on SLES11 has also been reported.
Not
all customers will be affected, but those, who are affected, may observe higher than
normal CPU consumption on their Linux environments where JVM's are utilized.
In Oracle Enterprise Manager ( EM ) , this problem can manifest itself as high CPU
consumption with the EM Agent process (which runs on a JVM in EM 12c, for
instance). It is possible that the OMS is also affected.
We
would advise customers to review the description of this problem in MOS
Note 1472651.1 and take action if they observe that their environment
is affected.
Contributed by Andrew Bulloch , Director, Application Systems Management Products
