impala常見錯誤

1、使用insert插入字元串報錯

ERROR: AnalysisException: Possible loss of precision for target table 'test.student'.

Expression ''e'' (type: STRING) would need to be cast to VARCHAR(22) for column 'name'

解決辦法：

insert into student values(123, CAST('aaa' AS varchar(22)));

字元串轉換下：CAST('xxx' AS varchar(12))

2、

E0127 19:28:25.289991 13469 impala-server.cc:339] ERROR: short-circuit local reads is disabled because

 - Impala cannot read or execute the parent directory of dfs.domain.socket.path

 - dfs.client.read.shortcircuit is not enabled.

ERROR: block location tracking is not properly enabled because

 - dfs.client.file-block-storage-locations.timeout is too low. It should be at least 3000.

E0127 19:28:25.290117 13469 impala-server.cc:341] Aborting Impala Server startup due to improper configuration

hdfs的配置檔案hdfs-site.xml增加如下内容：

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< property > < name >dfs.client.read.shortcircuit</ name > < value >true</ value > </ property > < property > < name >dfs.domain.socket.path</ name > < value> /var/hdfs-sockets/dn </value>   #手動隻需要建立 /var/hdfs-sockets目錄，dn會自動建立 </ property > < property > < name >dfs.client.file-block-storage-locations.timeout</ name > < value >3000</ value > </ property > < property > < name >dfs.datanode.hdfs-blocks-metadata.enabled</ name > < value >true</ value > </ property >