private void printUsageAndExit() {
    System.err.printf("Usage: hbase %s [options]%n", getClass().getName());
    System.err.println(" where [options] are:");
    System.err.println("  -h|-help         Show this help and exit.");
    System.err.println("  -threads <N>     Number of threads writing on the WAL.");
    System.err.println("  -regions <N>     Number of regions to open in the WAL. Default: 1");
    System.err.println("  -iterations <N>  Number of iterations per thread.");
    System.err.println("  -path <PATH>     Path where region's root directory is created.");
    System.err.println("  -families <N>    Number of column families to write.");
    System.err.println("  -qualifiers <N>  Number of qualifiers to write.");
    System.err.println("  -keySize <N>     Row key size in byte.");
    System.err.println("  -valueSize <N>   Row/Col value size in byte.");
    System.err.println("  -nocleanup       Do NOT remove test data when done.");
    System.err.println("  -noclosefs       Do NOT close the filesystem when done.");
    System.err.println("  -nosync          Append without syncing");
    System.err.println(
      "  -syncInterval <N> Append N edits and then sync. " + "Default=0, i.e. sync every edit.");
    System.err.println("  -verify          Verify edits written in sequence");
    System.err
      .println("  -verbose         Output extra info; " + "e.g. all edit seq ids when verifying");
    System.err.println("  -roll <N>        Roll the way every N appends");
    System.err.println("  -encryption <A>  Encrypt the WAL with algorithm A, e.g. AES");
    System.err.println("  -traceFreq <N>   Rate of trace sampling. Default: 1.0, "
      + "only respected when tracing is enabled, ie -Dhbase.trace.spanreceiver.classes=...");
    System.err.println("");
    System.err.println("Examples:");
    System.err.println("");
    System.err.println(" To run 100 threads on hdfs with log rolling every 10k edits and "
      + "verification afterward do:");
    System.err.println(" $ hbase org.apache.hadoop.hbase.wal." + "WALPerformanceEvaluation \\");
    System.err.println("    -conf ./core-site.xml -path hdfs://example.org:7000/tmp "
      + "-threads 100 -roll 10000 -verify");
    System.exit(1);
  }
Verify the content of the WAL file. Verify that the file has expected number of edits.
@param wals may not be null
@return Count of edits.
hbase-diagnostics/src/main/java/org/apache/hadoop/hbase/wal/WALPerformanceEvaluation.java