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Hudson commented on HBASE-18095: -------------------------------- Results for branch HBASE-18095/client-locate-meta-no-zookeeper [build #27 on builds.a.o|https://builds.apache.org/job/HBase%20Nightly/job/HBASE-18095%252Fclient-locate-meta-no-zookeeper/27/]: (x) *{color:red}-1 overall{color}* ---- details (if available): (/) {color:green}+1 general checks{color} -- For more information [see general report|https://builds.apache.org/job/HBase%20Nightly/job/HBASE-18095%252Fclient-locate-meta-no-zookeeper/27//General_Nightly_Build_Report/] (x) {color:red}-1 jdk8 hadoop2 checks{color} -- For more information [see jdk8 (hadoop2) report|https://builds.apache.org/job/HBase%20Nightly/job/HBASE-18095%252Fclient-locate-meta-no-zookeeper/27//JDK8_Nightly_Build_Report_(Hadoop2)/] (x) {color:red}-1 jdk8 hadoop3 checks{color} -- For more information [see jdk8 (hadoop3) report|https://builds.apache.org/job/HBase%20Nightly/job/HBASE-18095%252Fclient-locate-meta-no-zookeeper/27//JDK8_Nightly_Build_Report_(Hadoop3)/] (/) {color:green}+1 source release artifact{color} -- See build output for details. (/) {color:green}+1 client integration test{color} > Provide an option for clients to find the server hosting META that does not > involve the ZooKeeper client > -------------------------------------------------------------------------------------------------------- > > Key: HBASE-18095 > URL: https://issues.apache.org/jira/browse/HBASE-18095 > Project: HBase > Issue Type: New Feature > Components: Client > Reporter: Andrew Kyle Purtell > Assignee: Bharath Vissapragada > Priority: Major > Attachments: HBASE-18095.master-v1.patch, HBASE-18095.master-v2.patch > > > Clients are required to connect to ZooKeeper to find the location of the > regionserver hosting the meta table region. Site configuration provides the > client a list of ZK quorum peers and the client uses an embedded ZK client to > query meta location. Timeouts and retry behavior of this embedded ZK client > are managed orthogonally to HBase layer settings and in some cases the ZK > cannot manage what in theory the HBase client can, i.e. fail fast upon outage > or network partition. > We should consider new configuration settings that provide a list of > well-known master and backup master locations, and with this information the > client can contact any of the master processes directly. Any master in either > active or passive state will track meta location and respond to requests for > it with its cached last known location. If this location is stale, the client > can ask again with a flag set that requests the master refresh its location > cache and return the up-to-date location. Every client interaction with the > cluster thus uses only HBase RPC as transport, with appropriate settings > applied to the connection. The configuration toggle that enables this > alternative meta location lookup should be false by default. > This removes the requirement that HBase clients embed the ZK client and > contact the ZK service directly at the beginning of the connection lifecycle. > This has several benefits. ZK service need not be exposed to clients, and > their potential abuse, yet no benefit ZK provides the HBase server cluster is > compromised. Normalizing HBase client and ZK client timeout settings and > retry behavior - in some cases, impossible, i.e. for fail-fast - is no longer > necessary. > And, from [~ghelmling]: There is an additional complication here for > token-based authentication. When a delegation token is used for SASL > authentication, the client uses the cluster ID obtained from Zookeeper to > select the token identifier to use. So there would also need to be some > Zookeeper-less, unauthenticated way to obtain the cluster ID as well. -- This message was sent by Atlassian Jira (v8.3.4#803005)