JAVA-444: Add process information to UUID LSB

[pmaedel]

Java-444
For relevant discussion see also respective ticket for C*: CASSANDRA-7925

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[olim7t]

Yes, I agree that we need to address this.

Since using getRuntimeMXBean is not an "official" way to get the PID, I'd like to add the following:

• extract the actual number from the bean name, and log it at DEBUG level
• if the bean name has an unexpected format or an exception is thrown, fallback to the random number, but also log a WARN message
• allow the pid to be overridden by a system property (e.g. com.datastax.driver.PID). It would probably be a good idea to also mention that property in the warn message above.

@pmaedel, do you have time to take a look at this?

[pmaedel]

Well there is no single official way to get the PID, up until Java 9
With that in mind, I think we should go for the same solution as C*
@olim7t, could you add your proposal to CASSANDRA-7925 as well?

[olim7t]

C* uses Sigar to get the PID, amongst other things. That works well for them because Cassandra is a standalone program, they just need to include all Sigar files in the binary distribution and it's easy to reference them.

In our case it's a bit more complicated because the driver uses Maven for dependencies. Sigar is present in Maven central, but apparently it was deployed by a third party and I see a number of problems with it:

• not all platform-specific binaries are present (compare the list to what's present in Cassandra)
• some files in the repo don't follow Maven naming conventions, so I don't see how they could be referenced from our POM. For example: http://repo1.maven.org/maven2/org/fusesource/sigar/1.6.4/libsigar-universal64-macosx-1.6.4.dylib
• there's also a sigar-native.jar file containing all the platform-specific binaries, but it's not usable as-is, i.e. we can't just include it in our POM and expect Sigar to load from it. Apparently you're supposed to extract the files in a directory and pass the path as a system property, again something that's fine for a standalone program but not for a library like the driver.

Long story short, I think Sigar is too complicated for the driver, the getRuntimeMXBean solution should be good enough for most cases, provided we take the few precautions I outlined in my previous message.

[pmaedel]

@olim7t Thank you for elaborating. I agree with your reasoning and will look into the proposed adjustments asap.

[adutra]

Closing in favor of #593.