NameNode
startup
progress.See: Description
Interface | Description |
---|---|
StartupProgress.Counter |
Allows a caller to increment a counter for tracking progress.
|
Class | Description |
---|---|
StartupProgress |
StartupProgress is used in various parts of the namenode codebase to indicate
startup progress.
|
StartupProgressMetrics |
Links
StartupProgress to a MetricsSource to expose its
information via JMX. |
StartupProgressView |
StartupProgressView is an immutable, consistent, read-only view of namenode
startup progress.
|
Step |
A step performed by the namenode during a
Phase of startup. |
Enum | Description |
---|---|
Phase |
Indicates a particular phase of the namenode startup sequence.
|
Status |
Indicates run status of a
Phase . |
StepType |
Indicates a particular type of
Step . |
NameNode
startup
progress. The package models NameNode startup as a series of Phase
s,
with each phase further sub-divided into multiple Step
s. All phases
are coarse-grained and typically known in advance, implied by the structure of
the NameNode codebase (example: loading fsimage). Steps are more granular and
typically only known at runtime after startup begins (example: loading a
specific fsimage file with a known length from a particular location).
StartupProgress
provides a thread-safe data structure for
recording status information and counters. Various parts of the NameNode
codebase use this to describe the NameNode's activities during startup.
StartupProgressView
provides an immutable, consistent view of the
current state of NameNode startup progress. This can be used to present the
data to a user.
StartupProgressMetrics
exposes startup progress information via JMX
through the standard metrics system.Copyright © 2013 Apache Software Foundation. All rights reserved.