HBase on XGUGENG

How HMaster Detect Death of RegionServer

Fri, 06 Jul 2018 10:31:19 +0800

Step 3 of explanation about what happens after Full GC may be vague. It confuses audiences by

ServerManager on HMaster finds there must be something wrong with this RegionServer

How does HMaster detect the death of RegionServer?

RegionServer Stops after Full GC

Thu, 05 Jul 2018 16:31:24 +0800

One of the most devastating and unpredictable latency intruders is the Java Virtual Machine’s “stop the world” pauses for garbage collection (memory clean-up). This post troubleshoots an unexpected shutdown of RegionServer fundamentally caused by Full GC and makes the whole process clear.

A Troubleshooting for Threads Explosion in HBase Client

Fri, 09 Mar 2018 18:27:56 +0800

An issue, excessive threads of HBase client, annoyed me for a quite while. It reminds me to penetrate into uses of Executorservice in HBase client. That’s the origin of this blog.

HBase Batch Puts with BufferedMutator

Mon, 15 Jan 2018 16:56:23 +0800

BufferedMutator is meant for batched, potentially asynchronous puts into a single table. This class relies heavily on AsyncProcess, which I has explained here. Then, we can focus on what BufferedMutator does in this post.

HBase Batch Puts without BufferedMutator

Tue, 09 Jan 2018 11:33:34 +0800

For batch puts, it’s better if you construct a list of puts and then call HTable.put(final List<Put> puts), because it uses a single RPC call to commit the batch, but depending on the size of the list write buffer may flush it all or not.

In this post, BufferedMutator is excluded. It will be discussed in the near future.

Multiversion Concurrency Control in HBase

Wed, 27 Dec 2017 16:19:17 +0800

Multiversion Concurrency Control (MVCC for short) manages the read/write consistency, providing an interface for readers to determine what entries to ignore, and a mechanism for writers to obtain new write numbers, then “commit” the new writes for readers to read (thus forming atomic transactions).

A Lifecycle of HBase's Put: Server-side

Tue, 05 Dec 2017 15:14:28 +0800

Following the preceding A Lifecycle of HBase’s Put: Client-side, this post will figure out how a Put request does its mutation on HRegionServer. The whole process involves WAL, MemStore, and Coprocessor etc. After reading this post, hope you make their roles clear.

A Lifecycle of HBase's Put: Client-side

Fri, 24 Nov 2017 11:38:14 +0800

Put is used to perform insert or update a single row of HBase table. It’s essential to understand its lifecycle, which can be broke into two pieces,

Client-side, How the put request is built up and sent to the right RegionServer.
Server-side, How the RegionServer handle the Put request and update one row.

In view of the limitation of one single post, the client-side is discussed only.

HBase Code Analysis: MemStore

Thu, 23 Nov 2017 11:39:43 +0800

The MemStore holds in-memory modifications to the Store. This post deeps into the source code for sake of understanding what it really do underneath.

HBase Storage Internals

Thu, 16 Nov 2017 11:34:49 +0800

Overview

An HBase Table consists of multiple rows.
Table will be split into Regions based on rows’ lexicographical order.
A Store corresponds to a column family for a table for a given region.
A Store hosts a MemStore and 0 or more StoreFiles (HFiles).
The MemStore holds in-memory modifications to the Store.
StoreFiles are composed of Blocks.

How Does Client Find the Region

Fri, 08 Sep 2017 11:04:57 +0800

client-related source code is located in the module hbase-client.

A Mind Map for HBase

Sat, 01 Jul 2017 15:17:33 +0800

This map records my learning path to HBase. Every time I know something new about HBase, I will append it to this map.