Helpful Commands When Supporting Neo4j
Top 50 Slowest queries from Query log:
$ grep -i "INFO" query.log | sort -r -n -k 4 | head -50 > long_queries.log
Find Longest GC Pauses in debug or messages log:
$ grep -n -i blocked debug.log | sort -r -n -k 11 | head -10
Strip all comments / empty lines of neo4j.conf file:
$ grep -v "^#" neo4j.conf | sed -e '/^$/d' | sort
Find a class within a directory of jars:
$ for i in *.jar; do jar -tvf "$i" | grep -Hsi MyClass && echo "$i"; done
Take a thread dump:
$ jstack <neo4j process ID>
or to force a thread dump. Use when jstack <pid>
does not respond (process is hung)
$ sudo jstack -F <neo4j process ID>
Take a heap dump:
$ jmap -dump:format=b,file=<directory>/heapdump.hprof <neo4j process ID>
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