本文整理汇总了Java中org.apache.hadoop.hdfs.server.namenode.NNStorage.NameNodeFile.IMAGE_ROLLBACK属性的典型用法代码示例。如果您正苦于以下问题：Java NameNodeFile.IMAGE_ROLLBACK属性的具体用法？Java NameNodeFile.IMAGE_ROLLBACK怎么用？Java NameNodeFile.IMAGE_ROLLBACK使用的例子？那么恭喜您, 这里精选的属性代码示例或许可以为您提供帮助。您也可以进一步了解该属性所在类org.apache.hadoop.hdfs.server.namenode.NNStorage.NameNodeFile的用法示例。
在下文中一共展示了NameNodeFile.IMAGE_ROLLBACK属性的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Java代码示例。
示例1: purgeOldStorage
void purgeOldStorage(NameNodeFile nnf) throws IOException {
FSImageTransactionalStorageInspector inspector =
new FSImageTransactionalStorageInspector(EnumSet.of(nnf));
storage.inspectStorageDirs(inspector);
long minImageTxId = getImageTxIdToRetain(inspector);
purgeCheckpointsOlderThan(inspector, minImageTxId);
if (nnf == NameNodeFile.IMAGE_ROLLBACK) {
// do not purge edits for IMAGE_ROLLBACK.
return;
}
// If fsimage_N is the image we want to keep, then we need to keep
// all txns > N. We can remove anything < N+1, since fsimage_N
// reflects the state up to and including N. However, we also
// provide a "cushion" of older txns that we keep, which is
// handy for HA, where a remote node may not have as many
// new images.
//
// First, determine the target number of extra transactions to retain based
// on the configured amount.
long minimumRequiredTxId = minImageTxId + 1;
long purgeLogsFrom = Math.max(0, minimumRequiredTxId - numExtraEditsToRetain);
ArrayList<EditLogInputStream> editLogs = new ArrayList<EditLogInputStream>();
purgeableLogs.selectInputStreams(editLogs, purgeLogsFrom, false);
Collections.sort(editLogs, new Comparator<EditLogInputStream>() {
@Override
public int compare(EditLogInputStream a, EditLogInputStream b) {
return ComparisonChain.start()
.compare(a.getFirstTxId(), b.getFirstTxId())
.compare(a.getLastTxId(), b.getLastTxId())
.result();
}
});
// Remove from consideration any edit logs that are in fact required.
while (editLogs.size() > 0 &&
editLogs.get(editLogs.size() - 1).getFirstTxId() >= minimumRequiredTxId) {
editLogs.remove(editLogs.size() - 1);
}
// Next, adjust the number of transactions to retain if doing so would mean
// keeping too many segments around.
while (editLogs.size() > maxExtraEditsSegmentsToRetain) {
purgeLogsFrom = editLogs.get(0).getLastTxId() + 1;
editLogs.remove(0);
}
// Finally, ensure that we're not trying to purge any transactions that we
// actually need.
if (purgeLogsFrom > minimumRequiredTxId) {
throw new AssertionError("Should not purge more edits than required to "
+ "restore: " + purgeLogsFrom + " should be <= "
+ minimumRequiredTxId);
}
purgeableLogs.purgeLogsOlderThan(purgeLogsFrom);
}