update..

roles/common/files/etc/sysctl.d/50-redis.conf

@@ -0,0 +1,30 @@
+# -----
+# Running Redis Service (on LX-Container)
+#
+# See also changes at file /etc/rc.local
+# -----
+
+# Got this warning on redis logfile at LX-Container
+#
+#    # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn
+#    is set to the lower value of 128
+#
+net.core.somaxconn = 65535
+
+# Redis Server says:
+#
+# WARNING overcommit_memory is set to 0! Background save may fail under
+# low memory condition. To fix this issue add 'vm.overcommit_memory = 1'
+# to /etc/sysctl.conf and then reboot or run the command
+# 'sysctl vm.overcommit_memory=1' for this to take effect.
+vm.overcommit_memory = 1
+
+# increase Linux TCP buffer limits
+net.core.rmem_max = 67108864
+net.core.wmem_max = 67108864
+net.core.netdev_max_backlog = 262144
+
+# increase Linux autotuning TCP buffer limits
+# min, default, and max number of bytes to use
+net.ipv4.tcp_rmem = 4096 87380 33554432
+net.ipv4.tcp_wmem = 4096 87380 33554432