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https://issues.apache.org/jira/browse/STORM-876?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15021818#comment-15021818
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ASF GitHub Bot commented on STORM-876:
--------------------------------------
Github user bastiliu commented on a diff in the pull request:
https://github.com/apache/storm/pull/845#discussion_r45582877
--- Diff: storm-core/src/jvm/backtype/storm/blobstore/NimbusBlobStore.java
---
@@ -0,0 +1,419 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package backtype.storm.blobstore;
+
+import backtype.storm.Config;
+import backtype.storm.generated.AuthorizationException;
+import backtype.storm.generated.BeginDownloadResult;
+import backtype.storm.generated.ListBlobsResult;
+import backtype.storm.generated.ReadableBlobMeta;
+import backtype.storm.generated.SettableBlobMeta;
+import backtype.storm.generated.KeyAlreadyExistsException;
+import backtype.storm.generated.KeyNotFoundException;
+import backtype.storm.utils.NimbusClient;
+import backtype.storm.utils.Utils;
+import org.apache.thrift.TException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.NoSuchElementException;
+
+public class NimbusBlobStore extends ClientBlobStore {
+ private static final Logger LOG =
LoggerFactory.getLogger(NimbusBlobStore.class);
+
+ public class NimbusKeyIterator implements Iterator<String> {
+ private ListBlobsResult listBlobs = null;
+ private int offset = 0;
+ private boolean eof = false;
+
+ public NimbusKeyIterator(ListBlobsResult listBlobs) {
+ this.listBlobs = listBlobs;
+ this.eof = (listBlobs.get_keys_size() == 0);
+ }
+
+ private boolean isCacheEmpty() {
+ return listBlobs.get_keys_size() <= offset;
+ }
+
+ private void readMore() {
+ if (!eof) {
+ try {
+ offset = 0;
+ synchronized(client) {
+ listBlobs =
client.getClient().listBlobs(listBlobs.get_session());
+ }
+ if (listBlobs.get_keys_size() == 0) {
+ eof = true;
+ }
+ } catch (TException e) {
+ throw new RuntimeException(e);
+ }
+ }
+ }
+
+ @Override
+ public synchronized boolean hasNext() {
+ if (isCacheEmpty()) {
+ readMore();
+ }
+ return !eof;
+ }
+
+ @Override
+ public synchronized String next() {
+ if (!hasNext()) {
+ throw new NoSuchElementException();
+ }
+ String ret = listBlobs.get_keys().get(offset);
+ offset++;
+ return ret;
+ }
+
+ @Override
+ public void remove() {
+ throw new UnsupportedOperationException("Delete Not Supported");
+ }
+ }
+
+ public class NimbusDownloadInputStream extends InputStreamWithMeta {
+ private BeginDownloadResult beginBlobDownload;
+ private byte[] buffer = null;
+ private int offset = 0;
+ private int end = 0;
+ private boolean eof = false;
+
+ public NimbusDownloadInputStream(BeginDownloadResult
beginBlobDownload) {
+ this.beginBlobDownload = beginBlobDownload;
+ }
+
+ @Override
+ public long getVersion() throws IOException {
+ return beginBlobDownload.get_version();
+ }
+
+ @Override
+ public synchronized int read() throws IOException {
+ if (isEmpty()) {
+ readMore();
+ if (eof) {
+ return -1;
+ }
+ }
+ int length = Math.min(1, available());
+ if (length == 0) {
+ return -1;
+ }
+ int ret = buffer[offset];
+ offset += length;
+ return ret;
+ }
+
+ @Override
+ public synchronized int read(byte[] b, int off, int len) throws
IOException {
+ if (isEmpty()) {
+ readMore();
+ if (eof) {
+ return -1;
+ }
+ }
+ int length = Math.min(len, available());
+ System.arraycopy(buffer, offset, b, off, length);
+ offset += length;
+ return length;
+ }
+
+ private boolean isEmpty() {
+ return buffer == null || offset >= end;
+ }
+
+ private void readMore() {
+ if (!eof) {
+ try {
+ ByteBuffer buff;
+ synchronized(client) {
+ buff =
client.getClient().downloadBlobChunk(beginBlobDownload.get_session());
+ }
+ buffer = buff.array();
+ offset = buff.arrayOffset() + buff.position();
+ int length = buff.remaining();
+ end = offset + length;
+ if (length == 0) {
+ eof = true;
+ }
+ } catch (TException e) {
+ throw new RuntimeException(e);
--- End diff --
Is it better to just throw TException, instead of RuntimeException? Let
caller to decide what the further action for TExcetpion, since the latter one
will possibly cause the thread of caller crash. e.g. for supervisor, we have a
retry mechanism in Utils/downloadResourcesAsSupervisor. If RuntimeException,
the retry might not work. Same issue for other operations in this file.
> Dist Cache: Basic Functionality
> -------------------------------
>
> Key: STORM-876
> URL: https://issues.apache.org/jira/browse/STORM-876
> Project: Apache Storm
> Issue Type: Improvement
> Components: storm-core
> Reporter: Robert Joseph Evans
> Assignee: Robert Joseph Evans
> Attachments: DISTCACHE.md, DistributedCacheDesignDocument.pdf
>
>
> Basic functionality for the Dist Cache feature.
> As part of this a new API should be added to support uploading and
> downloading dist cache items. storm-core.ser, storm-conf.ser and storm.jar
> should be written into the blob store instead of residing locally. We need a
> default implementation of the blob store that does essentially what nimbus
> currently does and does not need anything extra. But having an HDFS backend
> too would be great for scalability and HA.
> The supervisor should provide a way to download and manage these blobs and
> provide a working directory for the worker process with symlinks to the
> blobs. It should also allow the blobs to be updated and switch the symlink
> atomically to point to the new blob once it is downloaded.
> All of this is already done by code internal to Yahoo! we are in the process
> of getting it ready to push back to open source shortly.
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