Package org.apache.hadoop.hbase.errorhandling

Class ForeignException

java.lang.Object
java.lang.Throwable
java.lang.Exception
java.io.IOException
org.apache.hadoop.hbase.errorhandling.ForeignException
All Implemented Interfaces:
Serializable
@Public public class ForeignException extends IOException
A ForeignException is an exception from another thread or process.

ForeignExceptions are sent to 'remote' peers to signal an abort in the face of failures. When serialized for transmission we encode using Protobufs to ensure version compatibility.

Foreign exceptions contain a Throwable as its cause. This can be a "regular" exception generated locally or a ProxyThrowable that is a representation of the original exception created on original 'remote' source. These ProxyThrowables have their their stacks traces and messages overridden to reflect the original 'remote' exception. The only way these ProxyThrowables are generated are by this class's deserialize(byte[]) method.

See Also:

  • Field Details

    • source

      private final String source
      Name of the throwable's source such as a host or thread name. Must be non-null.

  • Constructor Details

    • ForeignException

      public ForeignException(String source, Throwable cause)
      Create a new ForeignException that can be serialized. It is assumed that this came form a local source.

    • ForeignException

      public ForeignException(String source, String msg)
      Create a new ForeignException that can be serialized. It is assumed that this is locally generated.

  • Method Details

    • getSource

      public String getSource()

    • isRemote

      public boolean isRemote()
      The cause of a ForeignException can be an exception that was generated on a local in process thread, or a thread from a 'remote' separate process. If the cause is a ProxyThrowable, we know it came from deserialization which usually means it came from not only another thread, but also from a remote thread.
      Returns:
      true if went through deserialization, false if locally generated

    • toString

      public String toString()
      Overrides:
      toString in class Throwable

    • toStackTraceElementMessages

      private static List<org.apache.hadoop.hbase.shaded.protobuf.generated.ErrorHandlingProtos.StackTraceElementMessage> toStackTraceElementMessages(StackTraceElement[] trace)
      Convert a stack trace to list of StackTraceElement.
      Parameters:
      trace - the stack trace to convert to protobuf message
      Returns:
      null if the passed stack is null.

    • serialize

      public static byte[] serialize(String source, Throwable t)
      Converts a ForeignException to an array of bytes.
      Parameters:
      source - the name of the external exception source
      t - the "local" external exception (local)
      Returns:
      protobuf serialized version of ForeignException

    • deserialize

      public static ForeignException deserialize(byte[] bytes) throws IOException
      Takes a series of bytes and tries to generate an ForeignException instance for it.
      Returns:
      the ForeignExcpetion instance
      Throws:
      InvalidProtocolBufferException - if there was deserialization problem this is thrown.
      IOException

    • toStackTrace

      private static StackTraceElement[] toStackTrace(List<org.apache.hadoop.hbase.shaded.protobuf.generated.ErrorHandlingProtos.StackTraceElementMessage> traceList)
      Unwind a serialized array of ErrorHandlingProtos.StackTraceElementMessages to a StackTraceElements.
      Parameters:
      traceList - list that was serialized
      Returns:
      the deserialized list or null if it couldn't be unwound (e.g. wasn't set on the sender).