阿帕奇星火:JDBC连接不工作 [英] Apache Spark : JDBC connection not working
问题描述
我也问过这个问题,previously也,但没有得到任何答复(<一个href=\"http://stackoverflow.com/questions/29669420/not-able-to-connect-to-postgres-using-jdbc-in-pyspark-shell\">Not能够连接到使用pyspark外壳 JDBC)的Postgres。
我已经成功安装了星火1.3.0在我的本地Windows就跑示例程序使用pyspark外壳进行测试。
现在,我想从Mllib对存储在PostgreSQL中的数据相关性运行,但我不能够连接到PostgreSQL。
我已经成功地通过运行添加所需的jar在classpath(测试这个罐子)
pyspark --jarsC:\\路径\\为\\罐\\ PostgreSQL相关9.2-1002.jdbc3.jar
我可以看到,罐子环境UI添加成功。
当我运行pyspark外壳下面 -
从pyspark.sql进口SQLContext
sqlContext = SQLContext(SC)
DF = sqlContext.load(来源=JDBC,URL =的jdbc:在PostgreSQL:// [主持人] / [DBNAME],DBTABLE =[schema.table])
我得到这个错误 -
&GT;&GT;&GT; DF = sqlContext.load(来源=JDBC,URL =的jdbc:在PostgreSQL:// [主持人] / [DBNAME],DBTABLE =[schema.table])
回溯(最近通话最后一个):
文件&LT;&标准输入GT;,1号线,上述&lt;&模块GT;
文件C:\\用户\\ ACERNEW3 \\桌面\\星火\\火花1.3.0彬hadoop2.4 \\ python的\\ pyspark \\ SQL \\ context.py,线路482,在负荷
DF = self._ssql_ctx.load(源,joptions)
文件\"C:\\Users\\ACERNEW3\\Desktop\\Spark\\spark-1.3.0-bin-hadoop2.4\\python\\lib\\py4j-0.8.2.1-src.zip\\py4j\\java_gateway.py\",线538,在__call__
文件\"C:\\Users\\ACERNEW3\\Desktop\\Spark\\spark-1.3.0-bin-hadoop2.4\\python\\lib\\py4j-0.8.2.1-src.zip\\py4j\\protocol.py\",线300,在get_return_value
py4j.protocol.Py4JJavaError:同时呼吁o20.load发生错误。
:值java.sql.SQLException:PostgreSQL的:找到了JDBC没有合适的驱动程序// [主持人] / [DBNAME]
在java.sql.DriverManager.getConnection(DriverManager.java:602)
在java.sql.DriverManager.getConnection(DriverManager.java:207)
在org.apache.spark.sql.jdbc.JDBCRDD $ .resolveTable(JDBCRDD.scala:94)
在org.apache.spark.sql.jdbc.JDBCRelation&LT;&初始化GT; (JDBCRelation.scala:125)
在org.apache.spark.sql.jdbc.DefaultSource.createRelation(JDBCRelation.scala:114)
在org.apache.spark.sql.sources.ResolvedDataSource $。适用(ddl.scala:290)
在org.apache.spark.sql.SQLContext.load(SQLContext.scala:679)
在org.apache.spark.sql.SQLContext.load(SQLContext.scala:667)
在sun.reflect.NativeMethodAccessorImpl.invoke0(本机方法)
在sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
在sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
在java.lang.reflect.Method.invoke(Method.java:597)
在py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:231)
在py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:379)
在py4j.Gateway.invoke(Gateway.java:259)
在py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:133)
在py4j.commands.CallCommand.execute(CallCommand.java:79)
在py4j.GatewayConnection.run(GatewayConnection.java:207)
在java.lang.Thread.run(Thread.java:619)
我与MySQL / MariaDB的这个确切的问题,并获得重大线索由<一个href=\"http://stackoverflow.com/questions/30904182/pyspark-no-suitable-driver-found-for-jdbcmysql-dbhost\">this问题
所以,你pyspark命令应该是:
pyspark --conf spark.executor.extraClassPath =&LT;&了jdbc.jar GT; --driver类路径&LT;&了jdbc.jar GT; --jars&LT;&了jdbc.jar GT; --master&LT;主网址&GT;
同时还要注意是否有错误时,pyspark开始像警告:本地罐子......不存在,跳过。和ERROR SparkContext:罐未发现在...,这可能意味着你的拼写错误路径
I have asked this question previously also but did not got any answer (Not able to connect to postgres using jdbc in pyspark shell).
I have successfully installed Spark 1.3.0 on my local windows and ran sample programs to test using pyspark shell.
Now, I want to run Correlations from Mllib on the data that is stored in Postgresql, but I am not able to connect to postgresql.
I have successfully added the required jar (tested this jar) in the classpath by running
pyspark --jars "C:\path\to\jar\postgresql-9.2-1002.jdbc3.jar"
I can see that jar is successfully added in environment UI.
When I run the following in pyspark shell-
from pyspark.sql import SQLContext
sqlContext = SQLContext(sc)
df = sqlContext.load(source="jdbc",url="jdbc:postgresql://[host]/[dbname]", dbtable="[schema.table]")
I get this ERROR -
>>> df = sqlContext.load(source="jdbc",url="jdbc:postgresql://[host]/[dbname]", dbtable="[schema.table]")
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "C:\Users\ACERNEW3\Desktop\Spark\spark-1.3.0-bin-hadoop2.4\python\pyspark\sql\context.py", line 482, in load
df = self._ssql_ctx.load(source, joptions)
File "C:\Users\ACERNEW3\Desktop\Spark\spark-1.3.0-bin-hadoop2.4\python\lib\py4j-0.8.2.1-src.zip\py4j\java_gateway.py", line 538, in __call__
File "C:\Users\ACERNEW3\Desktop\Spark\spark-1.3.0-bin-hadoop2.4\python\lib\py4j-0.8.2.1-src.zip\py4j\protocol.py", line 300, in get_return_value
py4j.protocol.Py4JJavaError: An error occurred while calling o20.load.
: java.sql.SQLException: No suitable driver found for jdbc:postgresql://[host]/[dbname]
at java.sql.DriverManager.getConnection(DriverManager.java:602)
at java.sql.DriverManager.getConnection(DriverManager.java:207)
at org.apache.spark.sql.jdbc.JDBCRDD$.resolveTable(JDBCRDD.scala:94)
at org.apache.spark.sql.jdbc.JDBCRelation.<init> (JDBCRelation.scala:125)
at org.apache.spark.sql.jdbc.DefaultSource.createRelation(JDBCRelation.scala:114)
at org.apache.spark.sql.sources.ResolvedDataSource$.apply(ddl.scala:290)
at org.apache.spark.sql.SQLContext.load(SQLContext.scala:679)
at org.apache.spark.sql.SQLContext.load(SQLContext.scala:667)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:231)
at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:379)
at py4j.Gateway.invoke(Gateway.java:259)
at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:133)
at py4j.commands.CallCommand.execute(CallCommand.java:79)
at py4j.GatewayConnection.run(GatewayConnection.java:207)
at java.lang.Thread.run(Thread.java:619)
I had this exact problem with mysql/mariadb, and got BIG clue from this question
So your pyspark command should be:
pyspark --conf spark.executor.extraClassPath=<jdbc.jar> --driver-class-path <jdbc.jar> --jars <jdbc.jar> --master <master-URL>
Also watch for errors when pyspark start like "Warning: Local jar ... does not exist, skipping." and "ERROR SparkContext: Jar not found at ...", these probably mean you spelled the path wrong.
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