FAQ about startup failures - MaxCompute - Alibaba Cloud Documentation Center

This topic provides answers to some frequently asked questions about issues that occur when a task fails to start.

What do I do if the main class cannot be loaded?

Error message

Error: Cannot find or load the main class com.alibaba.proxima.CentauriRunner.

Solution
This issue occurs because MaxCompute fails to load the executable JAR package of Proxima CE. You can search for the DingTalk group ID 11782920 to join the MaxCompute developer community group for technical support.

What do I do if the specified delimiter is invalid?

Error message

FAILED: ODPS-0123131:User defined function exception - Traceback:
ProximaCEException(code=20003, msg=Parameter verification exception, detailMsg=The vector dimension [=1] in the data is different from the configured vector dimension [=128],)
        at com.alibaba.proxima.utils.VectorConvert.convert(VectorConvert.java:17)
        at com.alibaba.proxima.mr.BuildMapper.map(BuildMapper.java:58)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at com.aliyun.MaxCompute.mapred.bridge.utils.MapReduceUtils.runMapper(MapReduceUtils.java:120)
        at com.aliyun.MaxCompute.mapred.bridge.LotMapperUDTF.run(LotMapperUDTF.java:807)
        at com.aliyun.MaxCompute.udf.impl.batch.BatchStandaloneUDTFEvaluator.run(BatchStandaloneUDTFEvaluator.java:53)

Solution
Use the -vector_separator command-line parameter to specify a valid delimiter. The default delimiter is a tilde (~). For more information, see Optional parameters.
Note
The delimiter cannot be enclosed by single quotation marks (') or double quotation marks ("). For example, if a comma (,) is used as a delimiter and is enclosed by single quotation marks (''), the combination of the comma and the single quotation marks (',') is recognized as a string (',') instead of a delimiter (,).

What do I do if the JDK setting of a resource group is invalid?

Error message
Solution
When you create a MaxCompute task, the scheduling configuration includes multiple gateway resource groups. In most cases, one default resource group exists. The Java Development Kit (JDK) version must be V1.8 or later. If the preceding issue occurs, the JDK version may be outdated. You can manually change a resource group.

What do I do if the volume of a project cannot be found?

Error message

MaxCompute-0010000: System internal error - Lost volume dir

Error message

Solution

The directory of the volume may be damaged. You can manually delete the directory and rerun the code. To delete the directory, run the following commands:

vfs -ls /; -- List the directories that have the 'proxima_v2/xxx' prefix.
vfs -rm -r -f /proxima_v2/xxx; -- Delete the specified directory, which is the same as the volume directory that is recorded in run logs. You can run either this command or the following command.
vfs -rmv /proxima_v2; -- Delete the entire volume. You can run either this command or the preceding command.

What do I do if the error message "exceeds the allowed maximum length of '2097152'" appears?

Error message

MaxCompute-0420031: Invalid xml in HTTP request body - The request body is malformed or the server version doesn’t match this sdk/client. XML Schema validation failed: Element 'Value': [facet 'maxLength'] The value has a length of '7238452'; this exceeds the allowed maximum length of  '2097152'.

The startup parameter -classpath may be incorrectly configured. To resolve this issue, follow the instructions to correctly configure the -classpath parameter. For more information, see the "Run a basic vector search task" section in Basic vector search.

What do I do if the error message "java.lang.UnsatisfiedLinkError: no jniproxima in java library.path" appears?

Error message
Solution
In most cases, this issue occurs because a MapReduce task of MaxCompute fails to load the SDK for Proxima. This is because the machine on which the MapReduce task runs is outdated or the environment configuration of the MapReduce task is excessively low. The probability of this issue is low. If this issue occurs, rerun the task. This way, the system schedules the task to a machine that can run as expected.