Use sensible heap size for JVMs in Vagrant

- use -Xmx320M for Kafka processes instead of -Xmx1G -Xms1G
- use -Xmx192M for Kafka processes instead of -Xmx512M -Xms512M

Vagrantfile

@@ -4,6 +4,7 @@
 # Vagrantfile API/syntax version. Don't touch unless you know what you're doing!
 VAGRANTFILE_API_VERSION = "2"
 
+# We have 5 * 192MB ZK processes and 5 * 320MB Kafka processes => 2560MB
 MEMORY = 3072
 
 Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|

vagrant/kafka.conf

@@ -1,5 +1,9 @@
 start on started zookeeper-ZK_PORT
 stop on stopping zookeeper-ZK_PORT
 
-pre-start exec sleep 2
-exec /opt/kafka-KAFKAID/bin/kafka-server-start.sh /opt/kafka-KAFKAID/config/server.properties
+# Use a script instead of exec (using env stanza leaks KAFKA_HEAP_OPTS from zookeeper)
+script
+  sleep 2
+  export KAFKA_HEAP_OPTS="-Xmx320m"
+  exec /opt/kafka-KAFKAID/bin/kafka-server-start.sh /opt/kafka-KAFKAID/config/server.properties
+end script

vagrant/zookeeper.conf

@@ -1,4 +1,7 @@
 start on started toxiproxy
 stop on stopping toxiproxy
 
-exec /opt/kafka-KAFKAID/bin/zookeeper-server-start.sh /opt/kafka-KAFKAID/config/zookeeper.properties
+script
+  export KAFKA_HEAP_OPTS="-Xmx192m"
+  exec /opt/kafka-KAFKAID/bin/zookeeper-server-start.sh /opt/kafka-KAFKAID/config/zookeeper.properties
+end script