Detailed configuration parameters (mainly%zookeeper_home%/conf/zoo.cfg files)

detailed configuration parameters (mainly%zookeeper_home%/conf/zoo.cfg files)

Name of parameter	Description
ClientPort	The port where the client connects to the server, which is the external service port, is generally set to 2181.
DataDir	The directory where the snapshot file snapshot is stored. By default, the transaction log is also stored here. It is recommended to configure parameter Datalogdir at the same time, the write performance of transaction log directly affects ZK performance.
Ticktime	A time unit in ZK. All the time in ZK is based on this time unit, and is configured in integer times. For example, the minimum timeout for sessions is 2*ticktime.
Datalogdir	The transaction log output directory. Try to configure the output of the transaction log with a separate disk or mount point, which will greatly enhance ZK performance. (No Java system property)
Globaloutstandinglimit	Maximum request heap count. The default is 1000. When ZK runs, although the server is no longer idle to handle more client requests, it allows clients to submit requests to the server to improve throughput performance. Of course, to prevent server memory from overflowing, the request backlog is still limited. (Java system property:zookeeper.globaloutstandinglimit. )
preallocsize	Advance disk space for subsequent writes to the transaction log. The default is 64M, and the size of each transaction log is 64M. If ZK has a larger snapshot frequency, it is recommended that this parameter be reduced appropriately. (Java system Property:zookeeper.preallocsize )
Snapcount	After each snapcount transaction log output, a snapshot (snapshot) is triggered, at which point ZK generates a snapshot.* file and creates a new transaction log file log.*. The default is 100000. (in real code implementations, a certain number of random numbers are processed to prevent all servers from taking snapshots at the same time and impacting performance) (Java system property:Zookeeper.snapcount )
tracefile	Log for all requests, which can be used during normal debugging, but is not recommended for production environments and can severely affect performance. (Java system property:? requesttracefile )
Maxclientcnxns	The limit of the number of connections between a single client and a single server is IP level, the default is 60, and if set to 0, there is no limit. Note that the limit is limited to the number of connections between a single client machine and a single ZK server, not to the specified client IP, nor to the ZK cluster, nor to the number of connections that a single ZK has to all clients. To specify a restriction policy for client IP, here's a patch that you can try: http://rdc.taobao.com/team/jm/archives/1334 (No Java system property)
clientportaddress	For multiple network card machines, you can specify a different listening port for each IP.  By default, all IP listens to the port specified by clientport . New in 3.3.0
Minsessiontimeoutmaxsessiontimeout	The session timeout limit, which is enforced to the maximum or minimum time if the client sets a timeout that is not in this range. The default session timeout is 2 * ticktime ~ ~ Ticktime This range New in 3.3.0
Fsync.warningthresholdms	When the transaction log output, if the call to the Fsync method exceeds the specified timeout, the warning message is printed in the log. The default is 1000ms. (Java system Property: Fsync.warningthresholdms ) New in 3.3.4
Autopurge.purgeinterval	As already mentioned in the 3.4.0 and later versions, ZK provides the ability to automatically clean up transaction logs and snapshot files, which specifies the cleanup frequency, in hours, by configuring a 1 or larger integer, and by default 0, which means that the automatic cleanup function is not turned on.  (No Java system property) New in 3.4.0
Autopurge.snapretaincount	This parameter is used in combination with the above parameter, which specifies the number of files that need to be retained. The default is to keep 3.  (No Java system property) New in 3.4.0
Electionalg	In previous releases, this parameter configuration allowed us to choose the leader election algorithm, but since in future releases there will only be a "tcp-based version of fast leader election" algorithm, so this parameter is not currently used, This is not a detailed start. (No Java system property)
Initlimit	Follower during startup, all the latest data is synchronized from leader, and then the starting state of the service can be determined. Leader allows F to complete this work within Initlimit time. Normally, we don't have to worry too much about setting this parameter. If the ZK cluster data volume is indeed very large, f at the start, the time to synchronize data from the leader will also be longer, so in this case, it is necessary to adjust the appropriate size of the parameter. (No Java system property)
Synclimit	During the operation, leader is responsible for communicating with all the machines in the ZK cluster, such as through some heartbeat detection mechanism, to detect the machine's survival status. If L send a heartbeat packet after Synclimit and haven't received a response from F, then the f is considered to be out of line. Note: Do not set this parameter too large, or it may mask some problems. (No Java system property)
leaderserves	By default, leader accepts client connections and provides normal read-write services. However, if you want leader to focus on the coordination of the machines in the cluster, you can set this parameter to no, which will greatly improve the performance of the write operation. (Java system Property:zookeeper. leaderserves ).
server.x=[hostname]:nnnnn[:nnnnn]	The x here is a number that is the same as the ID in the myID file. The right can be configured with two ports, the first port for data synchronization between F and L and other communications, and the second port is used to leader voting during the election process. (No Java system property)
group.x=nnnnn[:nnnnn]weight.x=nnnnn	For machine grouping and weighting settings, see here (No Java system property)
Cnxtimeout	Leader during the election process, the timeout for opening a connection is 5s by default.  (Java system Property:zookeeper. cnxtimeout )
Zookeeper. Digestauthenticationprovider . superdigest	ZK permission settings related, see " using Super identity to the right node to operate" and " zookeeper rights control "
Skipacl	No ACL checks are made on all client requests. If a permission limit is set on the previous node, it will fail once the beginning of the server is opened. (Java system Property: Zookeeper.skipacl )
Forcesync	This parameter determines whether the FileChannel. Force needs to be invoked when the transaction log is committed to ensure that the data is fully synchronized to disk. (Java system Property: Zookeeper.forcesync )
Jute.maxbuffer	The maximum amount of data per node is 1M by default. This restriction must be set on both the server and the client side to take effect. (Java system Property: Jute.maxbuffer )