Cannot use forceSync=no to asynchronously write transaction logs. This is a critical bug, please address it ASAP. More details:
The class org.apache.zookeeper.server.persistence.FileTxnLog initializes forceSync property in a static block. However, the static variable is defined after the static block with a default value of true. Therefore, the value of the variable can never be false. Please move the declaration of the variable before the static block.