Andrew Purtell created HBASE-18095:
--------------------------------------
Summary: 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 Purtell
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.
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
