ZKFailoverController
E829912
ZKFailoverController is an HDFS high-availability component that uses ZooKeeper to coordinate automatic failover between NameNodes.
All labels observed (1)
| Label | Occurrences |
|---|---|
| ZKFailoverController canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T9925961 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: ZKFailoverController Context triple: [HDFS, hasComponent, ZKFailoverController]
-
A.
Apache ZooKeeper
Apache ZooKeeper is a centralized service for maintaining configuration information, naming, and distributed synchronization in large-scale distributed systems.
-
B.
Zab protocol
The Zab protocol is a crash-recovery atomic broadcast and consensus algorithm used by Apache ZooKeeper to ensure ordered, reliable updates across distributed nodes.
-
C.
ZKF
ZKF is the station code used to identify King’s Cross St Pancras Underground station on the London Underground network.
-
D.
HMaster
HMaster is the master server process in Apache HBase responsible for managing region servers, coordinating load balancing, and handling administrative operations for the HBase cluster.
-
E.
Paxos consensus algorithm
The Paxos consensus algorithm is a fault-tolerant protocol for achieving agreement among distributed systems, widely used as a foundation for reliable, replicated state machines and modern distributed databases.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: ZKFailoverController Target entity description: ZKFailoverController is an HDFS high-availability component that uses ZooKeeper to coordinate automatic failover between NameNodes.
-
A.
Apache ZooKeeper
Apache ZooKeeper is a centralized service for maintaining configuration information, naming, and distributed synchronization in large-scale distributed systems.
-
B.
Zab protocol
The Zab protocol is a crash-recovery atomic broadcast and consensus algorithm used by Apache ZooKeeper to ensure ordered, reliable updates across distributed nodes.
-
C.
ZKF
ZKF is the station code used to identify King’s Cross St Pancras Underground station on the London Underground network.
-
D.
HMaster
HMaster is the master server process in Apache HBase responsible for managing region servers, coordinating load balancing, and handling administrative operations for the HBase cluster.
-
E.
Paxos consensus algorithm
The Paxos consensus algorithm is a fault-tolerant protocol for achieving agreement among distributed systems, widely used as a foundation for reliable, replicated state machines and modern distributed databases.
- F. None of above. chosen
Statements (40)
| Predicate | Object |
|---|---|
| instanceOf |
HDFS component
ⓘ
ZooKeeper-based failover controller ⓘ high-availability controller ⓘ |
| belongsToModule |
Hadoop HDFS
ⓘ
linked to:
HDFS
|
| belongsToProject |
Apache Software Foundation Hadoop project
ⓘ
linked to:
Hadoop
|
| canBeUsedWith | manual failover as backup procedure ⓘ |
| coordinates | automatic failover between NameNodes ⓘ |
| dependsOn | reliable ZooKeeper quorum ⓘ |
| elects | active NameNode via ZooKeeper ⓘ |
| ensures | only one active NameNode at a time ⓘ |
| implements | automatic failover policy ⓘ |
| interactsWith |
FailoverController framework in Hadoop
ⓘ
NameNode RPC server ⓘ
linked to:
NameNode
ZooKeeper client library ⓘ
linked to:
Apache ZooKeeper
|
| isConfiguredIn |
core-site.xml
ⓘ
hdfs-site.xml ⓘ |
| isConfiguredWith |
fencing methods
ⓘ
health check parameters ⓘ |
| isDocumentedIn | Hadoop HDFS High Availability documentation ⓘ |
| isImplementedIn | Java ⓘ |
| isStartedBy | hdfs zkfc command ⓘ |
| logsTo | Hadoop log files ⓘ |
| manages |
active NameNode role
ⓘ
standby NameNode role ⓘ |
| monitors | NameNode health ⓘ |
| partOf |
Apache Hadoop
ⓘ
linked to:
Hadoop
HDFS high availability architecture ⓘ |
| performs |
fencing of previously active NameNode on failover
ⓘ
health monitoring via RPC to NameNode ⓘ |
| prevents | split-brain scenarios between NameNodes ⓘ |
| requires |
ZooKeeper ensemble
ⓘ
properly configured ZooKeeper ACLs ⓘ shared edits or Quorum Journal Manager setup ⓘ |
| runsAlongside | NameNode ⓘ |
| runsOn | NameNode host ⓘ |
| storesCoordinationStateIn |
ZooKeeper znodes
ⓘ
linked to:
Apache ZooKeeper
|
| supports | HDFS NameNode high availability ⓘ |
| supportsMode | automatic failover ⓘ |
| uses | Apache ZooKeeper ⓘ |
| wasIntroducedIn | Hadoop 2.x high-availability feature set ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: ZKFailoverController Description of subject: ZKFailoverController is an HDFS high-availability component that uses ZooKeeper to coordinate automatic failover between NameNodes.
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.