Using Breakpad Minidumps for Crash Reporting

The breakpad project is an open-source framework for crash reporting. Impala can use breakpad to record stack information and register values when any of the Impala-related daemons crash due to an error such as SIGSEGV or unhandled exceptions. The dump files are much smaller than traditional core dump files. The dump mechanism itself uses very little memory, which improves reliability if the crash occurs while the system is low on memory.

Using the Minidump Files for Problem Resolution

You can see in the Impala log files or in the Cloudera Manager charts for Impala when crash events occur that generate minidump files. Because each restart begins a new log file, the crashed message is always at or near the bottom of the log file. (There might be another later message if core dumps are also enabled.)

Typically, you provide minidump files to Cloudera Support as part of problem resolution, in the same way that you might provide a core dump. The Send Diagnostic Data under the Support menu in Cloudera Manager guides you through the process of selecting a time period and volume of diagnostic data, then collects the data from all hosts and transmits the relevant information for you.

  1. In Cloudera Manager, navigate to Impala service > Configuration.
  2. In the search field, type minidump.
  3. Set the following fields to configure breakpad minidumps.
    • minidump_path: Turn on or off generation of the minidump files.

      By default, a minidump file is generated when an Impala-related daemon crashes.

    • minidump_path: Specify the Location for minidump files.

      By default, all minidump files are written to the following location on the host where a crash occurs: /var/log/impala-minidumps/daemon_name

      The minidump files for impalad, catalogd, and statestored are each written to a separate directory.

      If you specify a relative path for this setting, the value is interpreted relative to the default minidump_path directory.

    • max_minidumps: Specify the number of minidump files.

      Like any files used for logging or troubleshooting, consider limiting the number of minidump files, or removing unneeded ones, depending on the amount of free storage space on the hosts in the cluster.

      Because the minidump files are only used for problem resolution, you can remove any such files that are not needed to debug current issues.

      The default for this setting is 9. A zero or negative value is interpreted as unlimited.

  4. Click Save Changes and restart Impala.
  5. To provide minidump files to Cloudera Support as part of problem resolution, in Cloudera Manager, navigate to Support > Send Diagnostic Data and follow the steps.