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How To Configure Database JVM (JavaVM) To Use /dev/urandom (In Order To Avoid JDBC Connection Delays Due To Lack Of Random Number Entropy) (Doc ID 1594701.1)

Last updated on SEPTEMBER 21, 2022

Applies to:

JDBC - Version and later
Information in this document applies to any platform.
JDBC connection establishment with 11.2.x databases uses a new connection mechanism (o5logon) that requires the use of random numbers. These numbers are typically generated by a special device (/dev/random). However, this random number generator relies on entropy in order to generate sufficiently random numbers. This entropy comes from things like mouse pointer movement and keyboard entry. When there is insufficient entropy, the random number generator will not return any numbers. When this happens, the o5logon used by the JDBC library stalls, and has to wait until sufficient entropy is available. To address this issue, /dev/urandom is used instead. This device does not block, so JDBC connection establishment is not delayed.


How do we force the database JVM to use /dev/urandom, instead of /dev/random?


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