Queries on ignite leads to unresponsive ignite node

Question

When we do select count(*) from table , whole ignite server becomes unresponsive for execution of query. Query execution time is also very high and become higher if number of records are higher.

Even if query takes long time, whole server should not become unresponsive (unable to even ssh), all other queries timeout. Apache ignite version 2.7.5

Apache Ignite version : 2.7.5

Ignite persistence is enabled (true)

2 node cluster in partitioned mode

RAM - 150 GB per node

JVM xms and xmx 20G

Number of records - 160 million

JVM options -

/usr/java/jdk1.8.0_144/bin/java -XX:+AggressiveOpts -server -Xms20g -Xmx20g -XX:+AlwaysPreTouch -XX:+UseG1GC -XX:+ScavengeBeforeFullGC -XX:+DisableExplicitGC -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/etappdata/ignite/logs/PROD/etail-prod-ignite76-163/logs -XX:+ExitOnOutOfMemoryError -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintGCDateStamps -XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=10 -XX:GCLogFileSize=100M -Xloggc:/etappdata/ignite/logs/PROD/etail-prod-ignite76-163/gc.log -XX:+PrintAdaptiveSizePolicy -XX:+UseTLAB -verbose:gc -XX:+ParallelRefProcEnabled -XX:+UseLargePages -XX:+AggressiveOpts -Djava.net.preferIPv4Stack=true -Djava.net.preferIPv4Addresses=true -Djava.net.preferIPv6Stack=false -Djava.net.preferIPv6Addresses=false -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=8996 -Dcom.sun.management.jmxremote.rmi.port=8996 -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.local.only=false -Djava.rmi.server.hostname=etail-prod-ignite76-163 -XX:MaxDirectMemorySize=4g -javaagent:/tmp/apminsight-javaagent-prod/apminsight-javaagent.jar -Dfile.encoding=UTF-8 -XX:+UseG1GC -DIGNITE_QUIET=false -DIGNITE_SUCCESS_FILE=/ignite/apache-ignite-2.7.5-bin/work/ignite_success_7d9ec20d-9728-475a-aa80-4355eb8eaf02 -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=49112 -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -DIGNITE_HOME=/ignite/apache-ignite-2.7.5-bin -DIGNITE_PROG_NAME=./bin/ignite.sh -cp /ignite/apache-ignite-2.7.5-bin/libs/:/ignite/apache-ignite-2.7.5-bin/libs/ignite-indexing/:/ignite/apache-ignite-2.7.5-bin/libs/ignite-spring/:/ignite/apache-ignite-2.7.5-bin/libs/licenses/ org.apache.ignite.startup.cmdline.CommandLineStartup config/config-cache.xml

Answer 1

For queries such as SELECT * FROM table (without WHERE) it is recommended to enable lazy mode so that Ignite will not try to store the entire result set on heap at once.

You can enable it via JDBC/ODBC driver properties/connection string or on SqlFieldsQuery.