Revert "Update sysctl settings to match new recommendations"

This reverts commit 559d9d9f.

concourse/tasks/run_behave_on_ccp_cluster.yml

@@ -24,42 +24,6 @@ run:
         install_python_hacks
     '"
 
-    # setting sysctl settings
-    while read LINE; do
-        host=$(echo $LINE | awk '{ print $3 }')
-        ssh -n centos@$host "sudo bash -c '
-            # minimal settings
-            sysctl -w kernel.shmall=\`expr \$(getconf _PHYS_PAGES) / 2\`
-            sysctl -w kernel.shmmax=\`expr \$(/sbin/sysctl -n kernel.shmall) \* \$(getconf PAGE_SIZE)\`
-            sysctl -w kernel.shmmni=4096
-            sysctl -w vm.overcommit_memory=2
-            sysctl -w vm.overcommit_ratio=95
-            sysctl -w net.ipv4.ip_local_port_range=\"10000 65535\"
-            # additional settings
-            sysctl -w kernel.sem=\"500 2048000 200 40960\"
-            sysctl -w kernel.sysrq=1
-            sysctl -w kernel.core_uses_pid=1
-            sysctl -w kernel.msgmnb=65536
-            sysctl -w kernel.msgmax=65536
-            sysctl -w kernel.msgmni=2048
-            sysctl -w net.ipv4.tcp_syncookies=1
-            sysctl -w net.ipv4.conf.default.accept_source_route=0
-            sysctl -w net.ipv4.tcp_max_syn_backlog=4096
-            sysctl -w net.ipv4.conf.all.arp_filter=1
-            sysctl -w net.core.netdev_max_backlog=10000
-            sysctl -w net.core.rmem_max=2097152
-            sysctl -w net.core.wmem_max=2097152
-            sysctl -w vm.swappiness=10
-            sysctl -w vm.zone_reclaim_mode=0
-            sysctl -w vm.dirty_expire_centisecs=500
-            sysctl -w vm.dirty_writeback_centisecs=100
-            sysctl -w vm.dirty_background_ratio=0
-            sysctl -w vm.dirty_ratio=0
-            sysctl -w vm.dirty_background_bytes=1610612736
-            sysctl -w vm.dirty_bytes=4294967296
-        '"
-    done <cluster_env_files/etc_hostfile
-
     ssh -t mdw "
         source /home/gpadmin/gpdb_src/concourse/scripts/common.bash
         install_python_requirements_on_multi_host /home/gpadmin/gpdb_src/gpMgmt/requirements-dev.txt