private void startSynchronousWrites() {
    int maxOplogSize = (Integer) stack.pop();
    String rollOplog = (String) stack.pop();
    // convery megabytes to bytes for DiskWriteAttributes creation
    long maxOplogSizeInBytes = maxOplogSize;
    maxOplogSizeInBytes = maxOplogSizeInBytes * 1024 * 1024;
    Properties props = new Properties();
    props.setProperty(MAX_OPLOG_SIZE, String.valueOf(maxOplogSizeInBytes));
    props.setProperty(ROLL_OPLOG, rollOplog);
    props.setProperty(DiskWriteAttributesImpl.SYNCHRONOUS_PROPERTY, "true");
    stack.push(new DiskWriteAttributesImpl(props));
  }
When a <code>synchronous-writes</code> element is encounter, we push a
{@link DiskWriteAttributes} for doing synchronous writes on the stack.
geode-core/src/main/java/org/apache/geode/internal/cache/xmlcache/CacheXmlParser.java