Pulsar configuration

Pulsar configuration can be managed via a series of configuration files contained in the conf directory of a Pulsar installation

• BookKeeper
• Broker
• Client
• Service discovery
• Log4j
• Log4j shell
• Standalone
• WebSocket
• Pulsar proxy
• ZooKeeper

BookKeeper

BookKeeper is a replicated log storage system that Pulsar uses for durable storage of all messages.

Name	Description	Default
bookiePort	The port on which the bookie server listens.	3181
allowLoopback	Whether the bookie is allowed to use a loopback interface as its primary interface (i.e. the interface used to establish its identity). By default, loopback interfaces are not allowed as the primary interface. Using a loopback interface as the primary interface usually indicates a configuration error. For example, it’s fairly common in some VPS setups to not configure a hostname or to have the hostname resolve to 127.0.0.1. If this is the case, then all bookies in the cluster will establish their identities as 127.0.0.1:3181 and only one will be able to join the cluster. For VPSs configured like this, you should explicitly set the listening interface.	false
listeningInterface	The network interface on which the bookie listens. If not set, the bookie will listen on all interfaces.	eth0
journalDirectory	The directory where Bookkeeper outputs its write-ahead log (WAL)	data/bookkeeper/journal
ledgerDirectories	The directory where Bookkeeper outputs ledger snapshots. This could define multiple directories to store snapshots separated by comma, for example ledgerDirectories=/tmp/bk1-data,/tmp/bk2-data. Ideally, ledger dirs and the journal dir are each in a different device, which reduces the contention between random I/O and sequential write. It is possible to run with a single disk, but performance will be significantly lower.	data/bookkeeper/ledgers
ledgerManagerType	The type of ledger manager used to manage how ledgers are stored, managed, and garbage collected. See BookKeeper Internals for more info.	hierarchical
zkLedgersRootPath	The root ZooKeeper path used to store ledger metadata. This parameter is used by the ZooKeeper-based ledger manager as a root znode to store all ledgers.	/ledgers
ledgerStorageClass	Ledger storage implementation class	org.apache.bookkeeper.bookie.storage.ldb.DbLedgerStorage
entryLogFilePreallocationEnabled	Enable or disable entry logger preallocation	true
logSizeLimit	Max file size of the entry logger, in bytes. A new entry log file will be created when the old one reaches the file size limitation.	1073741824
minorCompactionThreshold	Threshold of minor compaction. Entry log files whose remaining size percentage reaches below this threshold will be compacted in a minor compaction. If set to less than zero, the minor compaction is disabled.	0.2
minorCompactionInterval	Time interval to run minor compaction, in seconds. If set to less than zero, the minor compaction is disabled.	3600
majorCompactionThreshold	The threshold of major compaction. Entry log files whose remaining size percentage reaches below this threshold will be compacted in a major compaction. Those entry log files whose remaining size percentage is still higher than the threshold will never be compacted. If set to less than zero, the minor compaction is disabled.	0.5
majorCompactionInterval	The time interval to run major compaction, in seconds. If set to less than zero, the major compaction is disabled.	86400
compactionMaxOutstandingRequests	Sets the maximum number of entries that can be compacted without flushing. When compacting, the entries are written to the entrylog and the new offsets are cached in memory. Once the entrylog is flushed the index is updated with the new offsets. This parameter controls the number of entries added to the entrylog before a flush is forced. A higher value for this parameter means more memory will be used for offsets. Each offset consists of 3 longs. This parameter should not be modified unless you’re fully aware of the consequences.	100000
compactionRate	The rate at which compaction will read entries, in adds per second.	1000
isThrottleByBytes	Throttle compaction by bytes or by entries.	false
compactionRateByEntries	The rate at which compaction will read entries, in adds per second.	1000
compactionRateByBytes	Set the rate at which compaction reads entries. The unit is bytes added per second.	1000000
journalMaxSizeMB	Max file size of journal file, in megabytes. A new journal file will be created when the old one reaches the file size limitation.	2048
journalMaxBackups	The max number of old journal files to keep. Keeping a number of old journal files would help data recovery in special cases.	5
journalPreAllocSizeMB	How space to pre-allocate at a time in the journal.	16
journalWriteBufferSizeKB	The of the write buffers used for the journal.	64
journalRemoveFromPageCache	Whether pages should be removed from the page cache after force write.	true
journalAdaptiveGroupWrites	Whether to group journal force writes, which optimizes group commit for higher throughput.	true
journalMaxGroupWaitMSec	The maximum latency to impose on a journal write to achieve grouping.	1
journalAlignmentSize	All the journal writes and commits should be aligned to given size	4096
journalBufferedWritesThreshold	Maximum writes to buffer to achieve grouping	524288
journalFlushWhenQueueEmpty	If we should flush the journal when journal queue is empty	false
numJournalCallbackThreads	The number of threads that should handle journal callbacks	8
rereplicationEntryBatchSize	The number of max entries to keep in fragment for re-replication	5000
gcWaitTime	How long the interval to trigger next garbage collection, in milliseconds. Since garbage collection is running in background, too frequent gc will heart performance. It is better to give a higher number of gc interval if there is enough disk capacity.	900000
gcOverreplicatedLedgerWaitTime	How long the interval to trigger next garbage collection of overreplicated ledgers, in milliseconds. This should not be run very frequently since we read the metadata for all the ledgers on the bookie from zk.	86400000
flushInterval	How long the interval to flush ledger index pages to disk, in milliseconds. Flushing index files will introduce much random disk I/O. If separating journal dir and ledger dirs each on different devices, flushing would not affect performance. But if putting journal dir and ledger dirs on same device, performance degrade significantly on too frequent flushing. You can consider increment flush interval to get better performance, but you need to pay more time on bookie server restart after failure.	60000
bookieDeathWatchInterval	Interval to watch whether bookie is dead or not, in milliseconds	1000
zkServers	A list of one of more servers on which zookeeper is running. The server list can be comma separated values, for example: zkServers=zk1:2181,zk2:2181,zk3:2181.	localhost:2181
zkTimeout	ZooKeeper client session timeout in milliseconds Bookie server will exit if it received SESSION_EXPIRED because it was partitioned off from ZooKeeper for more than the session timeout JVM garbage collection, disk I/O will cause SESSION_EXPIRED. Increment this value could help avoiding this issue	30000
serverTcpNoDelay	This settings is used to enabled/disabled Nagle’s algorithm, which is a means of improving the efficiency of TCP/IP networks by reducing the number of packets that need to be sent over the network. If you are sending many small messages, such that more than one can fit in a single IP packet, setting server.tcpnodelay to false to enable Nagle algorithm can provide better performance.	true
openFileLimit	Max number of ledger index files could be opened in bookie server If number of ledger index files reaches this limitation, bookie server started to swap some ledgers from memory to disk. Too frequent swap will affect performance. You can tune this number to gain performance according your requirements.	0
pageSize	Size of a index page in ledger cache, in bytes A larger index page can improve performance writing page to disk, which is efficient when you have small number of ledgers and these ledgers have similar number of entries. If you have large number of ledgers and each ledger has fewer entries, smaller index page would improve memory usage.	8192
pageLimit	How many index pages provided in ledger cache If number of index pages reaches this limitation, bookie server starts to swap some ledgers from memory to disk. You can increment this value when you found swap became more frequent. But make sure pageLimit*pageSize should not more than JVM max memory limitation, otherwise you would got OutOfMemoryException. In general, incrementing pageLimit, using smaller index page would gain better performance in lager number of ledgers with fewer entries case If pageLimit is -1, bookie server will use 1/3 of JVM memory to compute the limitation of number of index pages.	0
readOnlyModeEnabled	If all ledger directories configured are full, then support only read requests for clients. If "readOnlyModeEnabled=true" then on all ledger disks full, bookie will be converted to read-only mode and serve only read requests. Otherwise the bookie will be shutdown. By default this will be disabled.	true
diskUsageThreshold	For each ledger dir, maximum disk space which can be used. Default is 0.95f. i.e. 95% of disk can be used at most after which nothing will be written to that partition. If all ledger dir partitions are full, then bookie will turn to readonly mode if ‘readOnlyModeEnabled=true’ is set, else it will shutdown. Valid values should be in between 0 and 1 (exclusive).	0.95
diskCheckInterval	Disk check interval in milli seconds, interval to check the ledger dirs usage.	10000
auditorPeriodicCheckInterval	Interval at which the auditor will do a check of all ledgers in the cluster. By default this runs once a week. The interval is set in seconds. To disable the periodic check completely, set this to 0. Note that periodic checking will put extra load on the cluster, so it should not be run more frequently than once a day.	604800
auditorPeriodicBookieCheckInterval	The interval between auditor bookie checks. The auditor bookie check, checks ledger metadata to see which bookies should contain entries for each ledger. If a bookie which should contain entries is unavailable, thea the ledger containing that entry is marked for recovery. Setting this to 0 disabled the periodic check. Bookie checks will still run when a bookie fails. The interval is specified in seconds.	86400
numAddWorkerThreads	number of threads that should handle write requests. if zero, the writes would be handled by netty threads directly.	0
numReadWorkerThreads	number of threads that should handle read requests. if zero, the reads would be handled by netty threads directly.	8
maxPendingReadRequestsPerThread	If read workers threads are enabled, limit the number of pending requests, to avoid the executor queue to grow indefinitely.	2500
readBufferSizeBytes	The number of bytes we should use as capacity for BufferedReadChannel.	4096
writeBufferSizeBytes	The number of bytes used as capacity for the write buffer	65536
useHostNameAsBookieID	Whether the bookie should use its hostname to register with the coordination service (e.g.: zookeeper service). When false, bookie will use its ipaddress for the registration.	false
statsProviderClass		org.apache.bookkeeper.stats.prometheus.PrometheusMetricsProvider
prometheusStatsHttpPort		8000
dbStorage_writeCacheMaxSizeMb	Size of Write Cache. Memory is allocated from JVM direct memory. Write cache is used to buffer entries before flushing into the entry log For good performance, it should be big enough to hold a sub	25% of direct memory
dbStorage_readAheadCacheMaxSizeMb	Size of Read cache. Memory is allocated from JVM direct memory. This read cache is pre-filled doing read-ahead whenever a cache miss happens	25% of direct memory
dbStorage_readAheadCacheBatchSize	How many entries to pre-fill in cache after a read cache miss	1000
dbStorage_rocksDB_blockCacheSize	Size of RocksDB block-cache. For best performance, this cache should be big enough to hold a significant portion of the index database which can reach ~2GB in some cases	10% of direct memory
dbStorage_rocksDB_writeBufferSizeMB		64
dbStorage_rocksDB_sstSizeInMB		64
dbStorage_rocksDB_blockSize		65536
dbStorage_rocksDB_bloomFilterBitsPerKey		10
dbStorage_rocksDB_numLevels		-1
dbStorage_rocksDB_numFilesInLevel0		4
dbStorage_rocksDB_maxSizeInLevel1MB		256
nettyMaxFrameSizeBytes	Set the maximum netty frame size in bytes. If the size of a received message is larger than the configured value, the message is rejected.	1 GB

Broker

Pulsar brokers are responsible for handling incoming messages from producers, dispatching messages to consumers, replicating data between clusters, and more.

Name	Description	Default
enablePersistentTopics	Whether persistent topics are enabled on the broker	true
enableNonPersistentTopics	Whether non-persistent topics are enabled on the broker	true
functionsWorkerEnabled	Whether the Pulsar Functions worker service is enabled in the broker	false
zookeeperServers	Zookeeper quorum connection string
zooKeeperCacheExpirySeconds	ZooKeeper cache expiry time in seconds	300
configurationStoreServers	Configuration store connection string (as a comma-separated list)
brokerServicePort	Broker data port	6650
brokerServicePortTls	Broker data port for TLS	6651
webServicePort	Port to use to server HTTP request	8080
webServicePortTls	Port to use to server HTTPS request	8443
webSocketServiceEnabled	Enable the WebSocket API service in broker	false
bindAddress	Hostname or IP address the service binds on, default is 0.0.0.0.	0.0.0.0
advertisedAddress	Hostname or IP address the service advertises to the outside world. If not set, the value of InetAddress.getLocalHost().getHostName() is used.
clusterName	Name of the cluster to which this broker belongs to
brokerDeduplicationEnabled	Sets the default behavior for message deduplication in the broker. If enabled, the broker will reject messages that were already stored in the topic. This setting can be overridden on a per-namespace basis.	false
brokerDeduplicationMaxNumberOfProducers	The maximum number of producers for which information will be stored for deduplication purposes.	10000
brokerDeduplicationEntriesInterval	The number of entries after which a deduplication informational snapshot is taken. A larger interval will lead to fewer snapshots being taken, though this would also lengthen the topic recovery time (the time required for entries published after the snapshot to be replayed).	1000
brokerDeduplicationProducerInactivityTimeoutMinutes	The time of inactivity (in minutes) after which the broker will discard deduplication information related to a disconnected producer.	360
dispatchThrottlingRatePerReplicatorInMsg	The default messages per second dispatch throttling-limit for every replicator in replication. The value of 0 means disabling replication message dispatch-throttling	0
dispatchThrottlingRatePerReplicatorInByte	The default bytes per second dispatch throttling-limit for every replicator in replication. The value of 0 means disabling replication message-byte dispatch-throttling	0
zooKeeperSessionTimeoutMillis	Zookeeper session timeout in milliseconds	30000
brokerShutdownTimeoutMs	Time to wait for broker graceful shutdown. After this time elapses, the process will be killed	60000
skipBrokerShutdownOnOOM	Flag to skip broker shutdown when broker handles Out of memory error.	false
backlogQuotaCheckEnabled	Enable backlog quota check. Enforces action on topic when the quota is reached	true
backlogQuotaCheckIntervalInSeconds	How often to check for topics that have reached the quota	60
backlogQuotaDefaultLimitGB	The default per-topic backlog quota limit	-1
allowAutoTopicCreation	Enable topic auto creation if a new producer or consumer connected	true
allowAutoTopicCreationType	The topic type (partitioned or non-partitioned) that is allowed to be automatically created.	Partitioned
allowAutoSubscriptionCreation	Enable subscription auto creation if a new consumer connected	true
defaultNumPartitions	The number of partitioned topics that is allowed to be automatically created if allowAutoTopicCreationType is partitioned	1
brokerDeleteInactiveTopicsEnabled	Enable the deletion of inactive topics. If topics are not consumed for some while, these inactive topics might be cleaned up. Deleting inactive topics is enabled by default. The default period is 1 minute.	true
brokerDeleteInactiveTopicsFrequencySeconds	How often to check for inactive topics	60
brokerDeleteInactiveTopicsMode	Set the mode to delete inactive topics. delete_when_no_subscriptions: delete the topic which has no subscriptions or active producers. delete_when_subscriptions_caught_up: delete the topic whose subscriptions have no backlogs and which has no active producers or consumers.	delete_when_no_subscriptions
brokerDeleteInactiveTopicsMaxInactiveDurationSeconds	Set the maximum duration for inactive topics. If it is not specified, the brokerDeleteInactiveTopicsFrequencySeconds parameter is adopted.	N/A
messageExpiryCheckIntervalInMinutes	How frequently to proactively check and purge expired messages	5
brokerServiceCompactionMonitorIntervalInSeconds	Interval between checks to see if topics with compaction policies need to be compacted	60
activeConsumerFailoverDelayTimeMillis	How long to delay rewinding cursor and dispatching messages when active consumer is changed.	1000
clientLibraryVersionCheckEnabled	Enable check for minimum allowed client library version	false
clientLibraryVersionCheckAllowUnversioned	Allow client libraries with no version information	true
statusFilePath	Path for the file used to determine the rotation status for the broker when responding to service discovery health checks
preferLaterVersions	If true, (and ModularLoadManagerImpl is being used), the load manager will attempt to use only brokers running the latest software version (to minimize impact to bundles)	false
maxNumPartitionsPerPartitionedTopic	Max number of partitions per partitioned topic. Use 0 or negative number to disable the check	0
tlsEnabled	Enable TLS	false
tlsCertificateFilePath	Path for the TLS certificate file
tlsKeyFilePath	Path for the TLS private key file
tlsTrustCertsFilePath	Path for the trusted TLS certificate file
tlsAllowInsecureConnection	Accept untrusted TLS certificate from client	false
tlsProtocols	Specify the tls protocols the broker will use to negotiate during TLS Handshake. Multiple values can be specified, separated by commas. Example:- TLSv1.2, TLSv1.1, TLSv1
tlsCiphers	Specify the tls cipher the broker will use to negotiate during TLS Handshake. Multiple values can be specified, separated by commas. Example:- TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
tlsEnabledWithKeyStore	Enable TLS with KeyStore type configuration in broker	false
tlsProvider	TLS Provider for KeyStore type
tlsKeyStoreType	LS KeyStore type configuration in broker: JKS, PKCS12	JKS
tlsKeyStore	TLS KeyStore path in broker
tlsKeyStorePassword	TLS KeyStore password for broker
brokerClientTlsEnabledWithKeyStore	Whether internal client use KeyStore type to authenticate with Pulsar brokers	false
brokerClientSslProvider	The TLS Provider used by internal client to authenticate with other Pulsar brokers
brokerClientTlsTrustStoreType	TLS TrustStore type configuration for internal client: JKS, PKCS12, used by the internal client to authenticate with Pulsar brokers	JKS
brokerClientTlsTrustStore	TLS TrustStore path for internal client, used by the internal client to authenticate with Pulsar brokers
brokerClientTlsTrustStorePassword	TLS TrustStore password for internal client, used by the internal client to authenticate with Pulsar brokers
brokerClientTlsCiphers	Specify the tls cipher the internal client will use to negotiate during TLS Handshake. (a comma-separated list of ciphers) e.g. [TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256]
brokerClientTlsProtocols	Specify the tls protocols the broker will use to negotiate during TLS handshake. (a comma-separated list of protocol names). e.g. [TLSv1.2, TLSv1.1, TLSv1]
ttlDurationDefaultInSeconds	The default ttl for namespaces if ttl is not configured at namespace policies.	0
tokenSecretKey	Configure the secret key to be used to validate auth tokens. The key can be specified like: tokenSecretKey=data:;base64,xxxxxxxxx or tokenSecretKey=file:///my/secret.key
tokenPublicKey	Configure the public key to be used to validate auth tokens. The key can be specified like: tokenPublicKey=data:;base64,xxxxxxxxx or tokenPublicKey=file:///my/secret.key
tokenPublicAlg	Configure the algorithm to be used to validate auth tokens. This can be any of the asymettric algorithms supported by Java JWT (https://github.com/jwtk/jjwt#signature-algorithms-keys)	RS256
tokenAuthClaim	Specify which of the token's claims will be used as the authentication "principal" or "role". The default "sub" claim will be used if this is left blank
tokenAudienceClaim	The token audience "claim" name, e.g. "aud", that will be used to get the audience from token. If not set, audience will not be verified.
tokenAudience	The token audience stands for this broker. The field tokenAudienceClaim of a valid token, need contains this.
maxUnackedMessagesPerConsumer	Max number of unacknowledged messages allowed to receive messages by a consumer on a shared subscription. Broker will stop sending messages to consumer once, this limit reaches until consumer starts acknowledging messages back. Using a value of 0, is disabling unackeMessage limit check and consumer can receive messages without any restriction	50000
maxUnackedMessagesPerSubscription	Max number of unacknowledged messages allowed per shared subscription. Broker will stop dispatching messages to all consumers of the subscription once this limit reaches until consumer starts acknowledging messages back and unack count reaches to limit/2. Using a value of 0, is disabling unackedMessage-limit check and dispatcher can dispatch messages without any restriction	200000
subscriptionRedeliveryTrackerEnabled	Enable subscription message redelivery tracker	true
subscriptionExpirationTimeMinutes	How long to delete inactive subscriptions from last consuming. Setting this configuration to a value greater than 0 deletes inactive subscriptions automatically. Setting this configuration to 0 does not delete inactive subscriptions automatically. Since this configuration takes effect on all topics, if there is even one topic whose subscriptions should not be deleted automatically, you need to set it to 0. Instead, you can set a subscription expiration time for each namespace using the pulsar-admin namespaces set-subscription-expiration-time options command.	0
maxConcurrentLookupRequest	Max number of concurrent lookup request broker allows to throttle heavy incoming lookup traffic	50000
maxConcurrentTopicLoadRequest	Max number of concurrent topic loading request broker allows to control number of zk-operations	5000
authenticationEnabled	Enable authentication	false
authenticationProviders	Authentication provider name list, which is comma separated list of class names
authorizationEnabled	Enforce authorization	false
superUserRoles	Role names that are treated as "super-user", meaning they will be able to do all admin operations and publish/consume from all topics
brokerClientAuthenticationPlugin	Authentication settings of the broker itself. Used when the broker connects to other brokers, either in same or other clusters
brokerClientAuthenticationParameters
athenzDomainNames	Supported Athenz provider domain names(comma separated) for authentication
exposePreciseBacklogInPrometheus	Enable expose the precise backlog stats, set false to use published counter and consumed counter to calculate, this would be more efficient but may be inaccurate.	false
bookkeeperMetadataServiceUri	Metadata service uri that bookkeeper is used for loading corresponding metadata driver and resolving its metadata service location. This value can be fetched using bookkeeper shell whatisinstanceid command in BookKeeper cluster. For example: zk+hierarchical://localhost:2181/ledgers. The metadata service uri list can also be semicolon separated values like below: zk+hierarchical://zk1:2181;zk2:2181;zk3:2181/ledgers
bookkeeperClientAuthenticationPlugin	Authentication plugin to use when connecting to bookies
bookkeeperClientAuthenticationParametersName	BookKeeper auth plugin implementation specifics parameters name and values
bookkeeperClientAuthenticationParameters
bookkeeperClientTimeoutInSeconds	Timeout for BK add / read operations	30
bookkeeperClientSpeculativeReadTimeoutInMillis	Speculative reads are initiated if a read request doesn’t complete within a certain time Using a value of 0, is disabling the speculative reads	0
bookkeeperNumberOfChannelsPerBookie	Number of channels per bookie	16
bookkeeperClientHealthCheckEnabled	Enable bookies health check. Bookies that have more than the configured number of failure within the interval will be quarantined for some time. During this period, new ledgers won’t be created on these bookies	true
bookkeeperClientHealthCheckIntervalSeconds		60
bookkeeperClientHealthCheckErrorThresholdPerInterval		5
bookkeeperClientHealthCheckQuarantineTimeInSeconds		1800
bookkeeperClientRackawarePolicyEnabled	Enable rack-aware bookie selection policy. BK will chose bookies from different racks when forming a new bookie ensemble	true
bookkeeperClientRegionawarePolicyEnabled	Enable region-aware bookie selection policy. BK will chose bookies from different regions and racks when forming a new bookie ensemble. If enabled, the value of bookkeeperClientRackawarePolicyEnabled is ignored	false
bookkeeperClientReorderReadSequenceEnabled	Enable/disable reordering read sequence on reading entries.	false
bookkeeperClientIsolationGroups	Enable bookie isolation by specifying a list of bookie groups to choose from. Any bookie outside the specified groups will not be used by the broker
bookkeeperClientSecondaryIsolationGroups	Enable bookie secondary-isolation group if bookkeeperClientIsolationGroups doesn't have enough bookie available.
bookkeeperClientMinAvailableBookiesInIsolationGroups	Minimum bookies that should be available as part of bookkeeperClientIsolationGroups else broker will include bookkeeperClientSecondaryIsolationGroups bookies in isolated list.
bookkeeperClientGetBookieInfoIntervalSeconds	Set the interval to periodically check bookie info	86400
bookkeeperClientGetBookieInfoRetryIntervalSeconds	Set the interval to retry a failed bookie info lookup	60
bookkeeperEnableStickyReads	Enable/disable having read operations for a ledger to be sticky to a single bookie. If this flag is enabled, the client will use one single bookie (by preference) to read all entries for a ledger.	true
managedLedgerDefaultEnsembleSize	Number of bookies to use when creating a ledger	2
managedLedgerDefaultWriteQuorum	Number of copies to store for each message	2
managedLedgerDefaultAckQuorum	Number of guaranteed copies (acks to wait before write is complete)	2
managedLedgerCacheSizeMB	Amount of memory to use for caching data payload in managed ledger. This memory is allocated from JVM direct memory and it’s shared across all the topics running in the same broker. By default, uses 1/5th of available direct memory
managedLedgerCacheCopyEntries	Whether we should make a copy of the entry payloads when inserting in cache	false
managedLedgerCacheEvictionWatermark	Threshold to which bring down the cache level when eviction is triggered	0.9
managedLedgerCacheEvictionFrequency	Configure the cache eviction frequency for the managed ledger cache (evictions/sec)	100.0
managedLedgerCacheEvictionTimeThresholdMillis	All entries that have stayed in cache for more than the configured time, will be evicted	1000
managedLedgerCursorBackloggedThreshold	Configure the threshold (in number of entries) from where a cursor should be considered 'backlogged' and thus should be set as inactive.	1000
managedLedgerDefaultMarkDeleteRateLimit	Rate limit the amount of writes per second generated by consumer acking the messages	1.0
managedLedgerMaxEntriesPerLedger	Max number of entries to append to a ledger before triggering a rollover. A ledger rollover is triggered on these conditions: Either the max rollover time has been reached or max entries have been written to the ledger and at least min-time has passed	50000
managedLedgerMinLedgerRolloverTimeMinutes	Minimum time between ledger rollover for a topic	10
managedLedgerMaxLedgerRolloverTimeMinutes	Maximum time before forcing a ledger rollover for a topic	240
managedLedgerCursorMaxEntriesPerLedger	Max number of entries to append to a cursor ledger	50000
managedLedgerCursorRolloverTimeInSeconds	Max time before triggering a rollover on a cursor ledger	14400
managedLedgerMaxUnackedRangesToPersist	Max number of "acknowledgment holes" that are going to be persistently stored. When acknowledging out of order, a consumer will leave holes that are supposed to be quickly filled by acking all the messages. The information of which messages are acknowledged is persisted by compressing in "ranges" of messages that were acknowledged. After the max number of ranges is reached, the information will only be tracked in memory and messages will be redelivered in case of crashes.	1000
autoSkipNonRecoverableData	Skip reading non-recoverable/unreadable data-ledger under managed-ledger’s list.It helps when data-ledgers gets corrupted at bookkeeper and managed-cursor is stuck at that ledger.	false
loadBalancerEnabled	Enable load balancer	true
loadBalancerPlacementStrategy	Strategy to assign a new bundle weightedRandomSelection
loadBalancerReportUpdateThresholdPercentage	Percentage of change to trigger load report update	10
loadBalancerReportUpdateMaxIntervalMinutes	maximum interval to update load report	15
loadBalancerHostUsageCheckIntervalMinutes	Frequency of report to collect	1
loadBalancerSheddingIntervalMinutes	Load shedding interval. Broker periodically checks whether some traffic should be offload from some over-loaded broker to other under-loaded brokers	30
loadBalancerSheddingGracePeriodMinutes	Prevent the same topics to be shed and moved to other broker more than once within this timeframe	30
loadBalancerBrokerMaxTopics	Usage threshold to allocate max number of topics to broker	50000
loadBalancerBrokerUnderloadedThresholdPercentage	Usage threshold to determine a broker as under-loaded	1
loadBalancerBrokerOverloadedThresholdPercentage	Usage threshold to determine a broker as over-loaded	85
loadBalancerResourceQuotaUpdateIntervalMinutes	Interval to update namespace bundle resource quota	15
loadBalancerBrokerComfortLoadLevelPercentage	Usage threshold to determine a broker is having just right level of load	65
loadBalancerAutoBundleSplitEnabled	enable/disable namespace bundle auto split	false
loadBalancerNamespaceBundleMaxTopics	maximum topics in a bundle, otherwise bundle split will be triggered	1000
loadBalancerNamespaceBundleMaxSessions	maximum sessions (producers + consumers) in a bundle, otherwise bundle split will be triggered	1000
loadBalancerNamespaceBundleMaxMsgRate	maximum msgRate (in + out) in a bundle, otherwise bundle split will be triggered	1000
loadBalancerNamespaceBundleMaxBandwidthMbytes	maximum bandwidth (in + out) in a bundle, otherwise bundle split will be triggered	100
loadBalancerNamespaceMaximumBundles	maximum number of bundles in a namespace	128
replicationMetricsEnabled	Enable replication metrics	true
replicationConnectionsPerBroker	Max number of connections to open for each broker in a remote cluster More connections host-to-host lead to better throughput over high-latency links.	16
replicationProducerQueueSize	Replicator producer queue size	1000
replicatorPrefix	Replicator prefix used for replicator producer name and cursor name pulsar.repl
replicationTlsEnabled	Enable TLS when talking with other clusters to replicate messages	false
defaultRetentionTimeInMinutes	Default message retention time. 0 means retention is disabled. -1 means data is not removed by time quota
defaultRetentionSizeInMB	Default retention size. 0 means retention is disabled. -1 means data is not removed by size quota	0
keepAliveIntervalSeconds	How often to check whether the connections are still alive	30
loadManagerClassName	Name of load manager to use	org.apache.pulsar.broker.loadbalance.impl.SimpleLoadManagerImpl
supportedNamespaceBundleSplitAlgorithms	Supported algorithms name for namespace bundle split	[range_equally_divide,topic_count_equally_divide]
defaultNamespaceBundleSplitAlgorithm	Default algorithm name for namespace bundle split	range_equally_divide
managedLedgerOffloadDriver	Driver to use to offload old data to long term storage (Possible values: S3)
managedLedgerOffloadMaxThreads	Maximum number of thread pool threads for ledger offloading	2
managedLedgerUnackedRangesOpenCacheSetEnabled	Use Open Range-Set to cache unacknowledged messages	true
managedLedgerOffloadDeletionLagMs	Delay between a ledger being successfully offloaded to long term storage and the ledger being deleted from bookkeeper	14400000
managedLedgerOffloadAutoTriggerSizeThresholdBytes	The number of bytes before triggering automatic offload to long term storage	-1 (disabled)
s3ManagedLedgerOffloadRegion	For Amazon S3 ledger offload, AWS region
s3ManagedLedgerOffloadBucket	For Amazon S3 ledger offload, Bucket to place offloaded ledger into
s3ManagedLedgerOffloadServiceEndpoint	For Amazon S3 ledger offload, Alternative endpoint to connect to (useful for testing)
s3ManagedLedgerOffloadMaxBlockSizeInBytes	For Amazon S3 ledger offload, Max block size in bytes. (64MB by default, 5MB minimum)	67108864
s3ManagedLedgerOffloadReadBufferSizeInBytes	For Amazon S3 ledger offload, Read buffer size in bytes (1MB by default)	1048576
s3ManagedLedgerOffloadRole	For Amazon S3 ledger offload, provide a role to assume before writing to s3
s3ManagedLedgerOffloadRoleSessionName	For Amazon S3 ledger offload, provide a role session name when using a role	pulsar-s3-offload
acknowledgmentAtBatchIndexLevelEnabled	Enable or disable the batch index acknowledgement.	false
maxMessageSize	Set the maximum size of a message.	5 MB
lazyCursorRecovery	Whether to recover cursors lazily when trying to recover a managed ledger backing a persistent topic. It can improve write availability of topics. The caveat is now when recovered ledger is ready to write we're not sure if all old consumers' last mark delete position(ack position) can be recovered or not. So user can make the trade off or have custom logic in application to checkpoint consumer state.	false

Client

The pulsar-client CLI tool can be used to publish messages to Pulsar and consume messages from Pulsar topics. This tool can be used in lieu of a client library.

Name	Description	Default
webServiceUrl	The web URL for the cluster.	http://localhost:8080/
brokerServiceUrl	The Pulsar protocol URL for the cluster.	pulsar://localhost:6650/
authPlugin	The authentication plugin.
authParams	The authentication parameters for the cluster, as a comma-separated string.
useTls	Whether or not TLS authentication will be enforced in the cluster.	false
tlsAllowInsecureConnection
tlsTrustCertsFilePath

Service discovery

Name	Description	Default
zookeeperServers	Zookeeper quorum connection string (comma-separated)
zooKeeperCacheExpirySeconds	ZooKeeper cache expiry time in seconds	300
configurationStoreServers	Configuration store connection string (as a comma-separated list)
zookeeperSessionTimeoutMs	ZooKeeper session timeout	30000
servicePort	Port to use to server binary-proto request	6650
servicePortTls	Port to use to server binary-proto-tls request	6651
webServicePort	Port that discovery service listen on	8080
webServicePortTls	Port to use to server HTTPS request	8443
bindOnLocalhost	Control whether to bind directly on localhost rather than on normal hostname	false
authenticationEnabled	Enable authentication	false
authenticationProviders	Authentication provider name list, which is comma separated list of class names (comma-separated)
authorizationEnabled	Enforce authorization	false
superUserRoles	Role names that are treated as "super-user", meaning they will be able to do all admin operations and publish/consume from all topics (comma-separated)
tlsEnabled	Enable TLS	false
tlsCertificateFilePath	Path for the TLS certificate file
tlsKeyFilePath	Path for the TLS private key file

Log4j

Name	Default
pulsar.root.logger	WARN,CONSOLE
pulsar.log.dir	logs
pulsar.log.file	pulsar.log
log4j.rootLogger	${pulsar.root.logger}
log4j.appender.CONSOLE	org.apache.log4j.ConsoleAppender
log4j.appender.CONSOLE.Threshold	DEBUG
log4j.appender.CONSOLE.layout	org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern	%d{ISO8601} - %-5p - [%t:%C{1}@%L] - %m%n
log4j.appender.ROLLINGFILE	org.apache.log4j.DailyRollingFileAppender
log4j.appender.ROLLINGFILE.Threshold	DEBUG
log4j.appender.ROLLINGFILE.File	${pulsar.log.dir}/${pulsar.log.file}
log4j.appender.ROLLINGFILE.layout	org.apache.log4j.PatternLayout
log4j.appender.ROLLINGFILE.layout.ConversionPattern	%d{ISO8601} - %-5p [%t:%C{1}@%L] - %m%n
log4j.appender.TRACEFILE	org.apache.log4j.FileAppender
log4j.appender.TRACEFILE.Threshold	TRACE
log4j.appender.TRACEFILE.File	pulsar-trace.log
log4j.appender.TRACEFILE.layout	org.apache.log4j.PatternLayout
log4j.appender.TRACEFILE.layout.ConversionPattern	%d{ISO8601} - %-5p [%t:%C{1}@%L][%x] - %m%n

Log4j shell

Name	Default
bookkeeper.root.logger	ERROR,CONSOLE
log4j.rootLogger	${bookkeeper.root.logger}
log4j.appender.CONSOLE	org.apache.log4j.ConsoleAppender
log4j.appender.CONSOLE.Threshold	DEBUG
log4j.appender.CONSOLE.layout	org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern	%d{ABSOLUTE} %-5p %m%n
log4j.logger.org.apache.zookeeper	ERROR
log4j.logger.org.apache.bookkeeper	ERROR
log4j.logger.org.apache.bookkeeper.bookie.BookieShell	INFO

Standalone

Name	Description	Default
zookeeperServers	The quorum connection string for local ZooKeeper
zooKeeperCacheExpirySeconds	ZooKeeper cache expiry time in seconds	300
configurationStoreServers	Configuration store connection string (as a comma-separated list)
brokerServicePort	The port on which the standalone broker listens for connections	6650
webServicePort	The port used by the standalone broker for HTTP requests	8080
bindAddress	The hostname or IP address on which the standalone service binds	0.0.0.0
advertisedAddress	The hostname or IP address that the standalone service advertises to the outside world. If not set, the value of InetAddress.getLocalHost().getHostName() is used.
clusterName	The name of the cluster that this broker belongs to.	standalone
zooKeeperSessionTimeoutMillis	The ZooKeeper session timeout, in milliseconds.	30000
brokerShutdownTimeoutMs	The time to wait for graceful broker shutdown. After this time elapses, the process will be killed.	60000
skipBrokerShutdownOnOOM	Flag to skip broker shutdown when broker handles Out of memory error.	false
backlogQuotaCheckEnabled	Enable the backlog quota check, which enforces a specified action when the quota is reached.	true
backlogQuotaCheckIntervalInSeconds	How often to check for topics that have reached the backlog quota.	60
backlogQuotaDefaultLimitGB	The default per-topic backlog quota limit.	10
ttlDurationDefaultInSeconds	The default ttl for namespaces if ttl is not configured at namespace policies.	0
brokerDeleteInactiveTopicsEnabled	Enable the deletion of inactive topics. If topics are not consumed for some while, these inactive topics might be cleaned up. Deleting inactive topics is enabled by default. The default period is 1 minute.	true
brokerDeleteInactiveTopicsFrequencySeconds	How often to check for inactive topics, in seconds.	60
messageExpiryCheckIntervalInMinutes	How often to proactively check and purged expired messages.	5
activeConsumerFailoverDelayTimeMillis	How long to delay rewinding cursor and dispatching messages when active consumer is changed.	1000
clientLibraryVersionCheckEnabled	Enable checks for minimum allowed client library version.	false
clientLibraryVersionCheckAllowUnversioned	Allow client libraries with no version information	true
statusFilePath	The path for the file used to determine the rotation status for the broker when responding to service discovery health checks	/usr/local/apache/htdocs
maxUnackedMessagesPerConsumer	The maximum number of unacknowledged messages allowed to be received by consumers on a shared subscription. The broker will stop sending messages to a consumer once this limit is reached or until the consumer begins acknowledging messages. A value of 0 disables the unacked message limit check and thus allows consumers to receive messages without any restrictions.	50000
maxUnackedMessagesPerSubscription	The same as above, except per subscription rather than per consumer.	200000
maxNumPartitionsPerPartitionedTopic	Max number of partitions per partitioned topic. Use 0 or negative number to disable the check	0
authenticationEnabled	Enable authentication for the broker.	false
authenticationProviders	A comma-separated list of class names for authentication providers.	false
authorizationEnabled	Enforce authorization in brokers.	false
superUserRoles	Role names that are treated as "superusers." Superusers are authorized to perform all admin tasks.
brokerClientAuthenticationPlugin	The authentication settings of the broker itself. Used when the broker connects to other brokers either in the same cluster or from other clusters.
brokerClientAuthenticationParameters	The parameters that go along with the plugin specified using brokerClientAuthenticationPlugin.
athenzDomainNames	Supported Athenz authentication provider domain names as a comma-separated list.
exposePreciseBacklogInPrometheus	Enable expose the precise backlog stats, set false to use published counter and consumed counter to calculate, this would be more efficient but may be inaccurate.	false
bookkeeperClientAuthenticationPlugin	Authentication plugin to be used when connecting to bookies (BookKeeper servers).
bookkeeperClientAuthenticationParametersName	BookKeeper authentication plugin implementation parameters and values.
bookkeeperClientAuthenticationParameters	Parameters associated with the bookkeeperClientAuthenticationParametersName
bookkeeperClientTimeoutInSeconds	Timeout for BookKeeper add and read operations.	30
bookkeeperClientSpeculativeReadTimeoutInMillis	Speculative reads are initiated if a read request doesn’t complete within a certain time. A value of 0 disables speculative reads.	0
bookkeeperClientHealthCheckEnabled	Enable bookie health checks.	true
bookkeeperClientHealthCheckIntervalSeconds	The time interval, in seconds, at which health checks are performed. New ledgers are not created during health checks.	60
bookkeeperClientHealthCheckErrorThresholdPerInterval	Error threshold for health checks.	5
bookkeeperClientHealthCheckQuarantineTimeInSeconds	If bookies have more than the allowed number of failures within the time interval specified by bookkeeperClientHealthCheckIntervalSeconds	1800
bookkeeperClientRackawarePolicyEnabled		true
bookkeeperClientRegionawarePolicyEnabled		false
bookkeeperClientReorderReadSequenceEnabled		false
bookkeeperClientIsolationGroups
bookkeeperClientSecondaryIsolationGroups	Enable bookie secondary-isolation group if bookkeeperClientIsolationGroups doesn't have enough bookie available.
bookkeeperClientMinAvailableBookiesInIsolationGroups	Minimum bookies that should be available as part of bookkeeperClientIsolationGroups else broker will include bookkeeperClientSecondaryIsolationGroups bookies in isolated list.
managedLedgerDefaultEnsembleSize		1
managedLedgerDefaultWriteQuorum		1
managedLedgerDefaultAckQuorum		1
managedLedgerCacheSizeMB		1024
managedLedgerCacheCopyEntries	Whether we should make a copy of the entry payloads when inserting in cache	false
managedLedgerCacheEvictionWatermark		0.9
managedLedgerCacheEvictionFrequency	Configure the cache eviction frequency for the managed ledger cache (evictions/sec)	100.0
managedLedgerCacheEvictionTimeThresholdMillis	All entries that have stayed in cache for more than the configured time, will be evicted	1000
managedLedgerCursorBackloggedThreshold	Configure the threshold (in number of entries) from where a cursor should be considered 'backlogged' and thus should be set as inactive.	1000
managedLedgerUnackedRangesOpenCacheSetEnabled	Use Open Range-Set to cache unacknowledged messages	true
managedLedgerDefaultMarkDeleteRateLimit		0.1
managedLedgerMaxEntriesPerLedger		50000
managedLedgerMinLedgerRolloverTimeMinutes		10
managedLedgerMaxLedgerRolloverTimeMinutes		240
managedLedgerCursorMaxEntriesPerLedger		50000
managedLedgerCursorRolloverTimeInSeconds		14400
autoSkipNonRecoverableData		false
loadBalancerEnabled		false
loadBalancerPlacementStrategy		weightedRandomSelection
loadBalancerReportUpdateThresholdPercentage		10
loadBalancerReportUpdateMaxIntervalMinutes		15
loadBalancerHostUsageCheckIntervalMinutes		1
loadBalancerSheddingIntervalMinutes		30
loadBalancerSheddingGracePeriodMinutes		30
loadBalancerBrokerMaxTopics		50000
loadBalancerBrokerUnderloadedThresholdPercentage		1
loadBalancerBrokerOverloadedThresholdPercentage		85
loadBalancerResourceQuotaUpdateIntervalMinutes		15
loadBalancerBrokerComfortLoadLevelPercentage		65
loadBalancerAutoBundleSplitEnabled		false
loadBalancerNamespaceBundleMaxTopics		1000
loadBalancerNamespaceBundleMaxSessions		1000
loadBalancerNamespaceBundleMaxMsgRate		1000
loadBalancerNamespaceBundleMaxBandwidthMbytes		100
loadBalancerNamespaceMaximumBundles		128
replicationMetricsEnabled		true
replicationConnectionsPerBroker		16
replicationProducerQueueSize		1000
replicationPolicyCheckDurationSeconds	Duration to check replication policy to avoid replicator inconsistency due to missing ZooKeeper watch. When the value is set to 0, disable checking replication policy.	600
defaultRetentionTimeInMinutes		0
defaultRetentionSizeInMB		0
keepAliveIntervalSeconds		30

WebSocket

Name	Description	Default
configurationStoreServers
zooKeeperSessionTimeoutMillis		30000
zooKeeperCacheExpirySeconds	ZooKeeper cache expiry time in seconds	300
serviceUrl
serviceUrlTls
brokerServiceUrl
brokerServiceUrlTls
webServicePort		8080
webServicePortTls		8443
bindAddress		0.0.0.0
clusterName
authenticationEnabled		false
authenticationProviders
authorizationEnabled		false
superUserRoles
brokerClientAuthenticationPlugin
brokerClientAuthenticationParameters
tlsEnabled		false
tlsAllowInsecureConnection		false
tlsCertificateFilePath
tlsKeyFilePath
tlsTrustCertsFilePath

Pulsar proxy

The Pulsar proxy can be configured in the conf/proxy.conf file.

Name	Description	Default
zookeeperServers	The ZooKeeper quorum connection string (as a comma-separated list)
configurationStoreServers	Configuration store connection string (as a comma-separated list)
zookeeperSessionTimeoutMs	ZooKeeper session timeout (in milliseconds)	30000
zooKeeperCacheExpirySeconds	ZooKeeper cache expiry time in seconds	300
servicePort	The port to use for server binary Protobuf requests	6650
servicePortTls	The port to use to server binary Protobuf TLS requests	6651
statusFilePath	Path for the file used to determine the rotation status for the proxy instance when responding to service discovery health checks
advertisedAddress	Hostname or IP address the service advertises to the outside world.	InetAddress.getLocalHost().getHostname()
authenticationEnabled	Whether authentication is enabled for the Pulsar proxy	false
authenticateMetricsEndpoint	Whether the '/metrics' endpoint requires authentication. Defaults to true. 'authenticationEnabled' must also be set for this to take effect.	true
authenticationProviders	Authentication provider name list (a comma-separated list of class names)
authorizationEnabled	Whether authorization is enforced by the Pulsar proxy	false
authorizationProvider	Authorization provider as a fully qualified class name	org.apache.pulsar.broker.authorization.PulsarAuthorizationProvider
brokerClientAuthenticationPlugin	The authentication plugin used by the Pulsar proxy to authenticate with Pulsar brokers
brokerClientAuthenticationParameters	The authentication parameters used by the Pulsar proxy to authenticate with Pulsar brokers
brokerClientTrustCertsFilePath	The path to trusted certificates used by the Pulsar proxy to authenticate with Pulsar brokers
superUserRoles	Role names that are treated as "super-users," meaning that they will be able to perform all admin
forwardAuthorizationCredentials	Whether client authorization credentials are forwarded to the broker for re-authorization. Authentication must be enabled via authenticationEnabled=true for this to take effect.	false
maxConcurrentInboundConnections	Max concurrent inbound connections. The proxy will reject requests beyond that.	10000
maxConcurrentLookupRequests	Max concurrent outbound connections. The proxy will error out requests beyond that.	50000
tlsEnabledInProxy	Whether TLS is enabled for the proxy	false
tlsEnabledWithBroker	Whether TLS is enabled when communicating with Pulsar brokers	false
tlsCertificateFilePath	Path for the TLS certificate file
tlsKeyFilePath	Path for the TLS private key file
tlsTrustCertsFilePath	Path for the trusted TLS certificate pem file
tlsHostnameVerificationEnabled	Whether the hostname is validated when the proxy creates a TLS connection with brokers	false
tlsRequireTrustedClientCertOnConnect	Whether client certificates are required for TLS. Connections are rejected if the client certificate isn’t trusted.	false
tlsProtocols	Specify the tls protocols the broker will use to negotiate during TLS Handshake. Multiple values can be specified, separated by commas. Example:- TLSv1.2, TLSv1.1, TLSv1
tlsCiphers	Specify the tls cipher the broker will use to negotiate during TLS Handshake. Multiple values can be specified, separated by commas. Example:- TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
tokenSecretKey	Configure the secret key to be used to validate auth tokens. The key can be specified like: tokenSecretKey=data:;base64,xxxxxxxxx or tokenSecretKey=file:///my/secret.key
tokenPublicKey	Configure the public key to be used to validate auth tokens. The key can be specified like: tokenPublicKey=data:;base64,xxxxxxxxx or tokenPublicKey=file:///my/secret.key
tokenPublicAlg	Configure the algorithm to be used to validate auth tokens. This can be any of the asymettric algorithms supported by Java JWT (https://github.com/jwtk/jjwt#signature-algorithms-keys)	RS256
tokenAuthClaim	Specify the token claim that will be used as the authentication "principal" or "role". The "subject" field will be used if this is left blank

ZooKeeper

ZooKeeper handles a broad range of essential configuration- and coordination-related tasks for Pulsar. The default configuration file for ZooKeeper is in the conf/zookeeper.conf file in your Pulsar installation. The following parameters are available:

Name	Description	Default
tickTime	The tick is the basic unit of time in ZooKeeper, measured in milliseconds and used to regulate things like heartbeats and timeouts. tickTime is the length of a single tick.	2000
initLimit	The maximum time, in ticks, that the leader ZooKeeper server allows follower ZooKeeper servers to successfully connect and sync. The tick time is set in milliseconds using the tickTime parameter.	10
syncLimit	The maximum time, in ticks, that a follower ZooKeeper server is allowed to sync with other ZooKeeper servers. The tick time is set in milliseconds using the tickTime parameter.	5
dataDir	The location where ZooKeeper will store in-memory database snapshots as well as the transaction log of updates to the database.	data/zookeeper
clientPort	The port on which the ZooKeeper server will listen for connections.	2181
autopurge.snapRetainCount	In ZooKeeper, auto purge determines how many recent snapshots of the database stored in dataDir to retain within the time interval specified by autopurge.purgeInterval (while deleting the rest).	3
autopurge.purgeInterval	The time interval, in hours, by which the ZooKeeper database purge task is triggered. Setting to a non-zero number will enable auto purge; setting to 0 will disable. Read this guide before enabling auto purge.	1
maxClientCnxns	The maximum number of client connections. Increase this if you need to handle more ZooKeeper clients.	60

In addition to the parameters in the table above, configuring ZooKeeper for Pulsar involves adding a server.N line to the conf/zookeeper.conf file for each node in the ZooKeeper cluster, where N is the number of the ZooKeeper node. Here's an example for a three-node ZooKeeper cluster:

server.1=zk1.us-west.example.com:2888:3888
server.2=zk2.us-west.example.com:2888:3888
server.3=zk3.us-west.example.com:2888:3888

We strongly recommend consulting the ZooKeeper Administrator's Guide for a more thorough and comprehensive introduction to ZooKeeper configuration