The issue above, specifically also containing error: java.lang.RuntimeException: Cannot create negative queue size seems to have been solved in Nifi v15.1 or v16!  See [NIFI-9433] Load Balanced Connections hangs / log "Cannot create negative queue size" - ASF JIRA (apache.org)   Myself, I  have an issue in the same high-level error "ConnectionLoadBalanceServer Failed to communicate with Peer node" , but a different (root)cause ( which I'm not sure yet how it is  caused , but must be related to network, our docker-swarm multi-node deployment OR a resource bottleneck): ... ERROR [Load-Balanced Client Thread-7] o.a.n.c.q.c.c.a.n.NioAsyncLoadBalanceClient Failed to communicate with Peer nifi2:8443 java.net.SocketTimeoutException: Timed out waiting for Peer nifi2:8443   ... View more

I did a quick research on why rhel7/centos7 still contains such an old mysql java connector/driver version (see "Redhat response"), and checked for working alternative RPMs (as installing via an rpm has many advantages vs a manual tarball install)   There are many working RPMs (I tested all of below, with CDH 6.2.0 and openjdk-8): - With Java >=v8, I recommend following: Ref: https://centos.pkgs.org/7/mysql-connectors-i386/mysql-connector-java-8.0.16-1.el7.noarch.rpm.html RPM: yum install http://repo.mysql.com/yum/mysql-connectors-community/el/7/i386//mysql-connector-java-8.0.16-1.el7.noarch.rpm   - With Java v7 you can try the latest 5.1.x from Fedora: Ref: https://fedora.pkgs.org/29/fedora-x86_64/mysql-connector-java-5.1.38-7.fc29.noarch.rpm.html RPM: http://download-ib01.fedoraproject.org/pub/fedora/linux/releases/29/Everything/x86_64/os/Packages/m/mysql-connector-java-5.1.38-7.fc29.noarch.rpm   - Find RPMs for other distros: https://pkgs.org/download/mysql-connector-java   - Official Redhat response: Alternatively, for Java-8, Redhat proposes to use the MariaDB client: https://bugzilla.redhat.com/show_bug.cgi?id=1684349#c7 > this is the best we could do for the customers who need a recent version of the JDBC driver for MySQL/MariaDB. More infos: https://developers.redhat.com/blog/2019/06/25/mariadb-10-3-now-available-on-red-hat-enterprise-linux-7/ For centos7: https://centos.pkgs.org/7/centos-sclo-rh-testing-x86_64/rh-mariadb103-mariadb-java-client-2.4.1-1.el7.noarch.rpm.html   I tested the 1-line yum install, but CDH would require more changes, due to the driver installed in /opt: yum install https://buildlogs.centos.org/centos/7/sclo/x86_64/rh/rh-mariadb103/rh-mariadb103-mariadb-java-client-2.4.1-1.el7.noarch.rpm https://buildlogs.centos.org/centos/7/sclo/x86_64/rh/rh-mariadb103/rh-mariadb103-runtime-3.3-3.el7.x86_64.rpm ... View more