Output PubSub+ Cache Instance Debug Information

To write the debug state of a PubSub+ Cache Instance to a file, you can run the service solcache debug command provided by the PubSub+ Cache service script. When this command is run, the script sends a SIGUSR2 signal to the PubSub+ Cache Instance, which prompts it to write its debug state to a file. The PubSub+ Cache Instance also generates a log to indicate the output file name.