Basic support of ES GC metrics for jvm9 (elastic#7628)

GC log format for JVM9 is more detailed than for JVM8.

Differences and possible improvements:
* To get cpu_times.* a corellation between log lines is required.
* Some GC metrics are available in jvm8 are not in jvm9
  (class_unload_time_sec, weak_refs_processing_time_sec, ...)
* heap.used_kb is empty, but it can be calculated as young_gen.used_kb +
  old_gen.size_kb
* GC phase times are logged in miliseconds vs seconds in jvm8

filebeat/module/elasticsearch/gc/ingest/pipeline.json

@@ -8,6 +8,8 @@
           "(?:%{JVM8HEADER}|%{JVM9HEADER}) Total time for which application threads were stopped: %{BASE10NUM:elasticsearch.gc.threads_total_stop_time_sec} seconds, Stopping threads took: %{BASE10NUM:elasticsearch.gc.stopping_threads_time_sec} seconds",
           "(?:%{JVM8HEADER}) \\[GC \\(%{DATA:elasticsearch.gc.phase.name}\\) \\[YG occupancy: %{BASE10NUM:elasticsearch.gc.young_gen.used_kb} K \\(%{BASE10NUM:elasticsearch.gc.young_gen.size_kb} K\\)\\]%{BASE10NUM}: \\[Rescan \\(parallel\\) , %{BASE10NUM:elasticsearch.gc.phase.parallel_rescan_time_sec} secs\\]%{BASE10NUM}: \\[weak refs processing, %{BASE10NUM:elasticsearch.gc.phase.weak_refs_processing_time_sec} secs\\]%{BASE10NUM}: \\[class unloading, %{BASE10NUM:elasticsearch.gc.phase.class_unload_time_sec} secs\\]%{BASE10NUM}: \\[scrub symbol table, %{BASE10NUM:elasticsearch.gc.phase.scrub_symbol_table_time_sec} secs\\]%{BASE10NUM}: \\[scrub string table, %{BASE10NUM:elasticsearch.gc.phase.scrub_string_table_time_sec} secs\\]\\[1 CMS-remark: %{BASE10NUM:elasticsearch.gc.old_gen.used_kb}K\\(%{BASE10NUM:elasticsearch.gc.old_gen.size_kb}K\\)\\] %{BASE10NUM:elasticsearch.gc.heap.used_kb}K\\(%{BASE10NUM:elasticsearch.gc.heap.size_kb}K\\), %{BASE10NUM:elasticsearch.gc.phase.duration_sec} secs\\] %{PROCTIME}",
           "(?:%{JVM8HEADER}) \\[GC \\(%{DATA:elasticsearch.gc.phase.name}\\) \\[%{BASE10NUM} CMS-initial-mark: %{BASE10NUM:elasticsearch.gc.old_gen.used_kb}K\\(%{BASE10NUM:elasticsearch.gc.old_gen.size_kb}K\\)\\] %{BASE10NUM:elasticsearch.gc.heap.used_kb}K\\(%{BASE10NUM:elasticsearch.gc.heap.size_kb}K\\), %{BASE10NUM:elasticsearch.gc.phase.duration_sec} secs\\] %{PROCTIME}",
+          "%{JVM9HEADER} GC\\(%{BASE10NUM}\\) ParNew: %{BASE10NUM}K-\\>%{BASE10NUM:elasticsearch.gc.young_gen.used_kb}K\\(%{BASE10NUM:elasticsearch.gc.young_gen.size_kb}K\\)",
+          "%{JVM9HEADER} GC\\(%{BASE10NUM}\\) Old: %{BASE10NUM}K-\\>%{BASE10NUM:elasticsearch.gc.old_gen.used_kb}K\\(%{BASE10NUM:elasticsearch.gc.old_gen.size_kb}K\\)",
           "(?:%{JVM8HEADER}|%{JVM9HEADER}) %{GREEDYMULTILINE:message}"
         ],
         "pattern_definitions": {
@@ -54,4 +56,4 @@
       }
     }
   ]
-}
+}