The ParallelScavenge + SerialOld garbage collector combination has been deprecated. Any use of the `UseParallelOldGC` command line option, which is used to enable this garbage collection algorithm combination, will cause a deprecation warning. The drop-in replacement is to use the ParallelScavenge + ParallelOld garbage collector through `-XX:+UseParallelGC` on the command line. See [JEP 366: Deprecate the ParallelScavenge + SerialOld GC Combination](https://openjdk.java.net/jeps/366) for more information.