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24.
分布式缓存 ...................................................................................................................................... 257
24.1.1.
缓存雪崩
.................................................................................................................................... 257
24.1.2.
缓存穿透
.................................................................................................................................... 257
24.1.3.
缓存预热
.................................................................................................................................... 257
24.1.4.
缓存更新
.................................................................................................................................... 257
24.1.5.
缓存降级
.................................................................................................................................... 257
25.
HADOOP ........................................................................................................................................ 259
25.1.1.
概念
............................................................................................................................................ 259
25.1.2.
HDFS ......................................................................................................................................... 259
25.1.2.1.
Client .................................................................................................................................................. 259
25.1.2.2.
NameNode ........................................................................................................................................ 259
25.1.2.3.
Secondary NameNode ................................................................................................................. 259
25.1.2.4.
DataNode......................................................................................................................................... 259
25.1.3.
MapReduce ............................................................................................................................... 260
25.1.3.1.
Client ................................................................................................................................................. 260
25.1.3.2.
JobTracker ....................................................................................................................................... 260
25.1.3.3.
TaskTracker ...................................................................................................................................... 261
25.1.3.4.
Task ................................................................................................................................................... 261
25.1.3.5.
Reduce Task 执行过程 ................................................................................................................... 261
25.1.4.
Hadoop MapReduce
作业的生命周期
................................................................................... 262
1.作业提交与初始化........................................................................................................................................... 262
2.任务调度与监控。........................................................................................................................................... 262
3.任务运行环境准备........................................................................................................................................... 262
4.任务执行 .......................................................................................................................................................... 262
5.作业完成。 ...................................................................................................................................................... 262
26.
SPARK ............................................................................................................................................ 263
26.1.1.
概念
............................................................................................................................................ 263
26.1.2.
核心架构
.................................................................................................................................... 263
Spark Core ......................................................................................................................................................... 263
Spark SQL .......................................................................................................................................................... 263
Spark Streaming ................................................................................................................................................ 263
Mllib ..................................................................................................................................................................... 263
GraphX ................................................................................................................................................................ 263
26.1.3.
核心组件
.................................................................................................................................... 264
Cluster Manager-制整个集群,监控 worker ................................................................................................. 264
Worker 节点-负责控制计算节点 ....................................................................................................................... 264
Driver: 运行 Application 的 main()函数......................................................................................................... 264
Executor:执行器,是为某个 Application 运行在 worker node 上的一个进程 .......................................... 264
26.1.4.
SPARK
编程模型
...................................................................................................................... 264
26.1.5.
SPARK
计算模型
...................................................................................................................... 265
26.1.6.
SPARK
运行流程
...................................................................................................................... 266
1.
构建 Spark Application 的运行环境,启动 SparkContext .................................................................... 267
2.
SparkContext 向资源管理器(可以是 Standalone,Mesos,Yarn)申请运行 Executor 资源,并启
动 StandaloneExecutorbackend, .................................................................................................................. 267
3.
Executor 向 SparkContext 申请 Task ..................................................................................................... 267
4.
SparkContext 将应用程序分发给 Executor ............................................................................................ 267
5.
SparkContext 构建成 DAG 图,将 DAG 图分解成 Stage、将 Taskset 发送给 Task Scheduler,最
后由 Task Scheduler 将 Task 发送给 Executor 运行 ..................................................................................... 267
6.
Task 在 Executor 上运行,运行完释放所有资源................................................................................... 267
26.1.7.
SPARK RDD
流程
.................................................................................................................... 267
26.1.8.
SPARK RDD ............................................................................................................................. 267
(1)RDD 的创建方式........................................................................................................................................... 267
(2)RDD 的两种操作算子(转换(Transformation)与行动(Action)) .............................................. 268
27.
STORM ........................................................................................................................................... 269