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>

  • Last Modified: 2020-09-30 15:12:37 UTC by Dave Gordon.
  • Relevant for Neo4j Versions: 3.1,3.2,3.3,3.4.
  • Relevant keywords cli, support.