Question

我已经创建了一个hive表，现在我想将snappy压缩数据加载到表中。因此我做了以下事情：

SET mapreduce.output.fileoutputformat.compress.codec=org.apache.hadoop.io.compress.SnappyCodec;
SET hive.exec.compress.output=true;
SET mapreduce.output.fileoutputformat.compress=true;
CREATE TABLE toydata_table (id STRING, value STRING)  ROW FORMAT DELIMITED FIELDS TERMINATED BY ",";'

然后我创建了名为toydata.csv的CSV文件，其中包含以下内容：

A,Value1
B,Value2
C,Value3

我通过执行

使用snzip（https://github.com/kubo/snzip）压缩此文件

/usr/local/bin/snzip -t snappy-java toydata.csv

产生toydata.csv.snappy。完成此操作后，我返回到hive cli并按LOAD DATA LOCAL INPATH "toydata.csv.snappy" INTO TABLE toydata_table;加载数据。但现在我想尝试从该表中查询并获得以下错误消息：

hive> select * from toydata_table;
OK
Exception in thread "main" java.lang.UnsatisfiedLinkError: org.apache.hadoop.util.NativeCodeLoader.buildSupportsSnappy()Z
    at org.apache.hadoop.util.NativeCodeLoader.buildSupportsSnappy(Native Method)
    at org.apache.hadoop.io.compress.SnappyCodec.checkNativeCodeLoaded(SnappyCodec.java:62)
    at org.apache.hadoop.io.compress.SnappyCodec.getDecompressorType(SnappyCodec.java:189)
    at org.apache.hadoop.io.compress.CodecPool.getDecompressor(CodecPool.java:175)
    at org.apache.hadoop.mapred.LineRecordReader.<init>(LineRecordReader.java:108)
    at org.apache.hadoop.mapred.TextInputFormat.getRecordReader(TextInputFormat.java:67)
    at org.apache.hadoop.hive.ql.exec.FetchOperator.getRecordReader(FetchOperator.java:433)
    at org.apache.hadoop.hive.ql.exec.FetchOperator.getNextRow(FetchOperator.java:515)
    at org.apache.hadoop.hive.ql.exec.FetchOperator.pushRow(FetchOperator.java:489)
    at org.apache.hadoop.hive.ql.exec.FetchTask.fetch(FetchTask.java:136)
    at org.apache.hadoop.hive.ql.Driver.getResults(Driver.java:1471)
    at org.apache.hadoop.hive.cli.CliDriver.processLocalCmd(CliDriver.java:271)
    at org.apache.hadoop.hive.cli.CliDriver.processCmd(CliDriver.java:216)
    at org.apache.hadoop.hive.cli.CliDriver.processLine(CliDriver.java:413)
    at org.apache.hadoop.hive.cli.CliDriver.executeDriver(CliDriver.java:781)
    at org.apache.hadoop.hive.cli.CliDriver.run(CliDriver.java:675)
    at org.apache.hadoop.hive.cli.CliDriver.main(CliDriver.java:614)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.apache.hadoop.util.RunJar.main(RunJar.java:212)

我使用gzip做了完全相同的事情并使用gzip工作正常。那么，为什么这部分会失败？

Answer 1

请在群集上安装snappy压缩编解码器。如果要确认是否安装了snappy，请在库中找到libsnappy.so文件。您还需要使用 - auxpath 参数启动配置单元shell并提供snappy.jar.eg：hive --auxpath /home/user/snappy1.0.4.1.jar

将snappy压缩数据写入配置单元表

1 个答案: