To make good use of Impala have a good comb structures, and he had to get him some problems exist in the place or need attention. This blog mainly want to record what sort of architecture on the Impala and the use of workaround.
Impala Profile
First, we look at positioning themselves in the Impala Impala Guide
Impala is an addition to tools available for querying big data. Impala does not replace the batch processing frameworks built on MapReduce such as Hive. Hive and other frameworks built on MapReduce are best suited for long running batch jobs, such as those involving batch processing of Extract, Transform, and Load (ETL) type jobs.
Impala think they complement the big data query tool for long batch work is recommended to use based mapreduce way to handle ultra large amounts of data. Because it is more stable and reliable.
Impala has now graduated from the Apache Incubator project, donated by the company Cloudera Impala by the Cloudera Impala => Apache Impala
Impala architecture section
Impala daemon (Impala Daemon)
Impala core component of a daemon running on each node of the cluster data, it is a process called impalad responsible for reading and writing data files. Receiving commands from impala-shell over, Hue, JDBC ODBC or transmitted by the inquiry; parallel query request and distribution of work throughout the cluster; intermediate query results be transmitted back to the central coordinator node.
Notice above I run on CDH with relevant examples impala, I'm just on a compute node started impala daemon, so that I want to use hue or impala request the node to build a query and return the results.
If you have more impala daemon, then I may have to submit any task on the impala daemon node. This example will serve as the query coordinator node. The other nodes of the query results are returned coordinating node, which will build the final result set.
Impala state storage process (Impala StateStore)
Impala is known as the statestore
Reference:
https://zhuanlan.zhihu.com/p/77463503 Apache Impala concept and architecture
https://impala.apache.org/docs/build/impala-3.2.pdf Apache Impala Guide
https://impala.apache.org/impala-docs.html Apache Impala Doc