[jira] [Commented] (MAPREDUCE-3315) Master-Worker Application on YARN
[ https://issues.apache.org/jira/browse/MAPREDUCE-3315?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13283209#comment-13283209 ] Nikhil S. Ketkar commented on MAPREDUCE-3315: - Sharad, you mean the following, right? {code} public interface MWProtocol { public static final long versionID = 1L; HeartbeatResponse heartBeat(Writable HeartbeatRequest); } public class HeartbeatResponse implements Writable { } public class HeartbeatRequest implements Writable { } // User extends MasterRunner and WorkerRunner public abstract class WorkerRunner { Writable doWork(Writable workUnit); // Abstract, implemented by user } public abstract class MasterRunner { public void addWorkers() { // Implementation } public void killWorkers() { // Implementation } public void assignWork(Writable workUnit) { // Implementation // uses heartBeat internally but HeartbeatResponse, HeartbeatRequest not exposed } public Writable waitForResult() { // Implementation // uses heartBeat internally but HeartbeatResponse, HeartbeatRequest not exposed } void manageWorkers(); // Abstract, implemented by user, can use addWorker(), killWorker(), assignWork() and waitForResult() } {code} Master-Worker Application on YARN - Key: MAPREDUCE-3315 URL: https://issues.apache.org/jira/browse/MAPREDUCE-3315 Project: Hadoop Map/Reduce Issue Type: New Feature Reporter: Sharad Agarwal Assignee: Sharad Agarwal Fix For: 0.24.0 Attachments: MAPREDUCE-3315-1.patch, MAPREDUCE-3315-2.patch, MAPREDUCE-3315-3.patch, MAPREDUCE-3315.patch Currently master worker scenarios are forced fit into Map-Reduce. Now with YARN, these can be first class and would benefit real/near realtime workloads and be more effective in using the cluster resources. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (MAPREDUCE-3315) Master-Worker Application on YARN
[ https://issues.apache.org/jira/browse/MAPREDUCE-3315?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13282237#comment-13282237 ] Sharad Agarwal commented on MAPREDUCE-3315: --- I meant the later one. The only difference is that I think it is better to not expose HeartbeatRequest and HeartbeatResponse to users beacause certain fields like actions etc are framework level. Instead these classes should composes the fields required by the user. Master-Worker Application on YARN - Key: MAPREDUCE-3315 URL: https://issues.apache.org/jira/browse/MAPREDUCE-3315 Project: Hadoop Map/Reduce Issue Type: New Feature Reporter: Sharad Agarwal Assignee: Sharad Agarwal Fix For: 0.24.0 Attachments: MAPREDUCE-3315-1.patch, MAPREDUCE-3315-2.patch, MAPREDUCE-3315-3.patch, MAPREDUCE-3315.patch Currently master worker scenarios are forced fit into Map-Reduce. Now with YARN, these can be first class and would benefit real/near realtime workloads and be more effective in using the cluster resources. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (MAPREDUCE-3315) Master-Worker Application on YARN
[ https://issues.apache.org/jira/browse/MAPREDUCE-3315?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13281561#comment-13281561 ] Nikhil S. Ketkar commented on MAPREDUCE-3315: - Sharad based on your comment: MWProtocol: Would be better to have a heartbeat kind of interface between worker and master via which worker sends the status reports and results of completed workunits as HeartbeatRequest and gets more WorkUnits and instructions as HeartbeatResponse. Using MWMessage for passing workunit and result is confusing. workunit and result could be just Writable objects. special instructions like kill should be given via separate Action commands in the HeartbeatResponse. Do you mean this? {code} public interface MWProtocol { public static final long versionID = 1L; Writable heartBeat(Writable workUnit); // User implements action commands and status reports himself // Worker implemented by the user should handle all action commands take appropriate action like dying and also send send status // Master implemented by the user should construct and send action commands, consume status report and take proper action } {code} Or this? {code} public interface MWProtocol { public static final long versionID = 1L; HeartbeatResponse heartBeat(Writable HeartbeatRequest); } public class HeartbeatResponse implements Writable { // This class has an action command which is hidden from the user // The framework will operate on the action command, like causing a worker to die // User extends this class to carry Work } public class HeartbeatRequest implements Writable { // This class has worker status which is hidden from the user // User extends this class to carry Result } {code} Or, did I misunderstand the comment? Master-Worker Application on YARN - Key: MAPREDUCE-3315 URL: https://issues.apache.org/jira/browse/MAPREDUCE-3315 Project: Hadoop Map/Reduce Issue Type: New Feature Reporter: Sharad Agarwal Assignee: Sharad Agarwal Fix For: 0.24.0 Attachments: MAPREDUCE-3315-1.patch, MAPREDUCE-3315-2.patch, MAPREDUCE-3315-3.patch, MAPREDUCE-3315.patch Currently master worker scenarios are forced fit into Map-Reduce. Now with YARN, these can be first class and would benefit real/near realtime workloads and be more effective in using the cluster resources. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (MAPREDUCE-3315) Master-Worker Application on YARN
[ https://issues.apache.org/jira/browse/MAPREDUCE-3315?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13280147#comment-13280147 ] Sharad Agarwal commented on MAPREDUCE-3315: --- Thanks Nikhil. Overall a good start. Needs some changes primarily to make the framework scalable and fault tolerant. Specific comments as follows: - MWProtocol: Would be better to have a heartbeat kind of interface between worker and master via which worker sends the status reports and results of completed workunits as HeartbeatRequest and gets more WorkUnits and instructions as HeartbeatResponse. Using MWMessage for passing workunit and result is confusing. workunit and result could be just Writable objects. special instructions like kill should be given via separate Action commands in the HeartbeatResponse. - MWWorkerRunner: If unable to contact Master for sometime, then worker should do a suicide - MWMasterRunner: if doesn't receive the heartbeat from worker for certain time period, then mark the worker as killed and launch a new worker. (The assumption is that doWork in is idempotent). - AMRMProtocolWraper: requestContainer() is currently blocking. This will have a high startup cost if number of workers are high. - MWApplicationMaster: addWorker: is blocking. Requests container and container launch is sequential. Will have high worker startup cost. Should be done via a thread pool for parallel launches. See ContainerLauncher in MR application master. For each worker launch, a new ContainerManagerWrapper thread is created. This is not scalable. - Extend org.apache.hadoop.yarn.service.AbstractService or CompositeService for all moving components - Add code comments. Javadocs to public and protected methods. - Add unit tests. - Dynamic worker pool: minWorker/maxWorkers. Needs client protocol say MWClientProtocol to see the status of the overall application. Potentially submit new workunits, kill workers, add workers etc. Master-Worker Application on YARN - Key: MAPREDUCE-3315 URL: https://issues.apache.org/jira/browse/MAPREDUCE-3315 Project: Hadoop Map/Reduce Issue Type: New Feature Reporter: Sharad Agarwal Assignee: Sharad Agarwal Fix For: 0.24.0 Attachments: MAPREDUCE-3315-1.patch, MAPREDUCE-3315-2.patch, MAPREDUCE-3315-3.patch, MAPREDUCE-3315.patch Currently master worker scenarios are forced fit into Map-Reduce. Now with YARN, these can be first class and would benefit real/near realtime workloads and be more effective in using the cluster resources. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (MAPREDUCE-3315) Master-Worker Application on YARN
[ https://issues.apache.org/jira/browse/MAPREDUCE-3315?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13280149#comment-13280149 ] Nikhil S. Ketkar commented on MAPREDUCE-3315: - Thanks. Will address these comments and submit a patch, ASAP. Master-Worker Application on YARN - Key: MAPREDUCE-3315 URL: https://issues.apache.org/jira/browse/MAPREDUCE-3315 Project: Hadoop Map/Reduce Issue Type: New Feature Reporter: Sharad Agarwal Assignee: Sharad Agarwal Fix For: 0.24.0 Attachments: MAPREDUCE-3315-1.patch, MAPREDUCE-3315-2.patch, MAPREDUCE-3315-3.patch, MAPREDUCE-3315.patch Currently master worker scenarios are forced fit into Map-Reduce. Now with YARN, these can be first class and would benefit real/near realtime workloads and be more effective in using the cluster resources. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (MAPREDUCE-3315) Master-Worker Application on YARN
[ https://issues.apache.org/jira/browse/MAPREDUCE-3315?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13246166#comment-13246166 ] Sharad Agarwal commented on MAPREDUCE-3315: --- Thanks Nikhil for the patch. Will have a look at it. Master-Worker Application on YARN - Key: MAPREDUCE-3315 URL: https://issues.apache.org/jira/browse/MAPREDUCE-3315 Project: Hadoop Map/Reduce Issue Type: New Feature Reporter: Sharad Agarwal Assignee: Sharad Agarwal Fix For: 0.24.0 Attachments: MAPREDUCE-3315.patch Currently master worker scenarios are forced fit into Map-Reduce. Now with YARN, these can be first class and would benefit real/near realtime workloads and be more effective in using the cluster resources. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (MAPREDUCE-3315) Master-Worker Application on YARN
[ https://issues.apache.org/jira/browse/MAPREDUCE-3315?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13246258#comment-13246258 ] Robert Joseph Evans commented on MAPREDUCE-3315: You could use an ephemeral port rather then limiting the set of ports needed. either way you are going to need to send the port to the workers probably as an environment variable. Without it workers could join with the incorrect master, and a malicious or buggy master could accept them and steal the worker. Master-Worker Application on YARN - Key: MAPREDUCE-3315 URL: https://issues.apache.org/jira/browse/MAPREDUCE-3315 Project: Hadoop Map/Reduce Issue Type: New Feature Reporter: Sharad Agarwal Assignee: Sharad Agarwal Fix For: 0.24.0 Attachments: MAPREDUCE-3315-1.patch, MAPREDUCE-3315.patch Currently master worker scenarios are forced fit into Map-Reduce. Now with YARN, these can be first class and would benefit real/near realtime workloads and be more effective in using the cluster resources. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (MAPREDUCE-3315) Master-Worker Application on YARN
[ https://issues.apache.org/jira/browse/MAPREDUCE-3315?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13246609#comment-13246609 ] Robert Joseph Evans commented on MAPREDUCE-3315: If you pass in a port number of 0 the OS will pick a free port. You can then query the server to know what port it actually bound to. Master-Worker Application on YARN - Key: MAPREDUCE-3315 URL: https://issues.apache.org/jira/browse/MAPREDUCE-3315 Project: Hadoop Map/Reduce Issue Type: New Feature Reporter: Sharad Agarwal Assignee: Sharad Agarwal Fix For: 0.24.0 Attachments: MAPREDUCE-3315-1.patch, MAPREDUCE-3315-2.patch, MAPREDUCE-3315.patch Currently master worker scenarios are forced fit into Map-Reduce. Now with YARN, these can be first class and would benefit real/near realtime workloads and be more effective in using the cluster resources. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (MAPREDUCE-3315) Master-Worker Application on YARN
[ https://issues.apache.org/jira/browse/MAPREDUCE-3315?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13246622#comment-13246622 ] Nikhil S. Ketkar commented on MAPREDUCE-3315: - I am using org.apache.hadoop.ipc.RPC.getServer(Class protocol, Object instance, String bindAddress, int port, Configuration conf) to create a RPC server as follows. {code} int linuxEphemeralPortRangeStart = 32768; int linuxEphemeralPortRangeEnd = 61000; int port = -1; for(int i = linuxEphemeralPortRangeStart; i = linuxEphemeralPortRangeEnd; i++) { try { server = RPC.getServer(MWProtocol.class, this, hostname, i, conf); port = i; break; } catch (BindException e) { } } if (port == -1) throw new BindException(); else { server.start(); return port; {code} Does RPC.getServer also pick a free port if 0 is specified? I tried to dig around but found not find any information. What code should I be looking at to confirm this? Master-Worker Application on YARN - Key: MAPREDUCE-3315 URL: https://issues.apache.org/jira/browse/MAPREDUCE-3315 Project: Hadoop Map/Reduce Issue Type: New Feature Reporter: Sharad Agarwal Assignee: Sharad Agarwal Fix For: 0.24.0 Attachments: MAPREDUCE-3315-1.patch, MAPREDUCE-3315-2.patch, MAPREDUCE-3315.patch Currently master worker scenarios are forced fit into Map-Reduce. Now with YARN, these can be first class and would benefit real/near realtime workloads and be more effective in using the cluster resources. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (MAPREDUCE-3315) Master-Worker Application on YARN
[ https://issues.apache.org/jira/browse/MAPREDUCE-3315?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13246635#comment-13246635 ] Robert Joseph Evans commented on MAPREDUCE-3315: Yes it does. {code} server = RPC.getServer(MWProtocol.class, this, hostname, 0, conf); port = server.getPort(); server.start(); {code} Master-Worker Application on YARN - Key: MAPREDUCE-3315 URL: https://issues.apache.org/jira/browse/MAPREDUCE-3315 Project: Hadoop Map/Reduce Issue Type: New Feature Reporter: Sharad Agarwal Assignee: Sharad Agarwal Fix For: 0.24.0 Attachments: MAPREDUCE-3315-1.patch, MAPREDUCE-3315-2.patch, MAPREDUCE-3315.patch Currently master worker scenarios are forced fit into Map-Reduce. Now with YARN, these can be first class and would benefit real/near realtime workloads and be more effective in using the cluster resources. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (MAPREDUCE-3315) Master-Worker Application on YARN
[ https://issues.apache.org/jira/browse/MAPREDUCE-3315?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13245108#comment-13245108 ] Sharad Agarwal commented on MAPREDUCE-3315: --- can have it in hadoop-yarn-applications module. Example app could be sub-module of the master-worker app. Master-Worker Application on YARN - Key: MAPREDUCE-3315 URL: https://issues.apache.org/jira/browse/MAPREDUCE-3315 Project: Hadoop Map/Reduce Issue Type: New Feature Reporter: Sharad Agarwal Assignee: Sharad Agarwal Fix For: 0.24.0 Currently master worker scenarios are forced fit into Map-Reduce. Now with YARN, these can be first class and would benefit real/near realtime workloads and be more effective in using the cluster resources. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (MAPREDUCE-3315) Master-Worker Application on YARN
[ https://issues.apache.org/jira/browse/MAPREDUCE-3315?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13245600#comment-13245600 ] Vinod Kumar Vavilapalli commented on MAPREDUCE-3315: We have a hadoop-yarn/hadoop-yarn-applications/ module under which you can put your framework (as a sibling to hadoop-yarn-applications-distributedshell/). The example could go as a sub-module under yours. Taking a step back, I think you should start with writing down the APIs: (1) The client API for submission and getting the app-status. (2) The task API: which the users can override and provide their own impl. Advanced: (3) The master API: as to how to order the tasks (a queue?) etc. Master-Worker Application on YARN - Key: MAPREDUCE-3315 URL: https://issues.apache.org/jira/browse/MAPREDUCE-3315 Project: Hadoop Map/Reduce Issue Type: New Feature Reporter: Sharad Agarwal Assignee: Sharad Agarwal Fix For: 0.24.0 Attachments: MAPREDUCE-3315.patch Currently master worker scenarios are forced fit into Map-Reduce. Now with YARN, these can be first class and would benefit real/near realtime workloads and be more effective in using the cluster resources. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (MAPREDUCE-3315) Master-Worker Application on YARN
[ https://issues.apache.org/jira/browse/MAPREDUCE-3315?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13246011#comment-13246011 ] Nikhil S. Ketkar commented on MAPREDUCE-3315: - Here is a brief description of the API in the current patch. This is quite preliminary and I will be improving on this based on feedback. In order to implement a new Master-Worker job, the user has to implement 4 classes, which are, WorkUnit, ResultUnit, Master and Worker. The WorkUnit and ResultUnit classes extend the MWMessage class which is an abstract class and is placed in the Master-Worker framework. Similarly, Master extends the MWApplicationMaster and Worker extends the MWWorkerRunner. Lets look at each of the classes one by one. Here is the code for the WorkUnit. Note that here, a single integer has been added as a payload and it represents the data that the Master will populate and the Worker will work on. The framework passes around MWMessage objects and is unaware of the additional data that might be contained in the MWMessage. It is the users reponsibility to populate and extract the payload information (in the Master and Worker classes) and also provide methods to serialize and deserialize the payload data. {code} public class WorkUnit extends MWMessage { int data; public int getData() { return data; } public void setData(int data) { this.data = data; } @Override public void writeWorkUnit(DataOutput out) throws IOException { out.writeInt(data); } @Override public void readFieldsWorkUnit(DataInput in) throws IOException { data = in.readInt(); } } {code} Similarly, here is the code for the ResultUnit. For our simple example its quite identical to the WorkUnit. As with the WorkUnit, the result unit also contains the payload and its the users responsibility to populate and extract the payload and provide functionality to serialize and deserialize the payload. {code} public class ResultUnit extends MWMessage { int data; public int getData() { return data; } public void setData(int data) { this.data = data; } @Override public void writeWorkUnit(DataOutput out) throws IOException { out.writeInt(data); } @Override public void readFieldsWorkUnit(DataInput in) throws IOException { data = in.readInt(); } {code} Now lets look at the API for the Worker. Any Worker should extend the MWWorkerRunner class. It should override the doWork method which basically receives a WorkUnit and returns a ResultUnit. For this simple example, I am simply populating the ResultUnit with the data in the WorkUnit. {code} public class MWWorker extends MWWorkerRunner { public static void main(String[] args) { MWWorker curr = new MWWorker(); try { curr.init(localhost, 16001); } catch (InterruptedException e) { e.printStackTrace(); } } @Override public MWMessage doWork(MWMessage workUnit) { ResultUnit result = new ResultUnit(); int got = ((WorkUnit) workUnit).getData(); result.setData(got); return result; } } {code} Now, on to the Master. Any Master extends the MWApplicationMaster class and overrides the manageWorkers method. There are 4 methods in MWApplicationMaster that the master can use. The addWorker method which simply adds a worker. Similarly, there is a killWorker method that kills a worker. This basically allows the user to add workers and get rid of them based on the work load. To assign work, the user can use the addWork method which takes the WorkUnit as a parameter. This is a non-blocking call. To get a ResultUnit the user can use the waitForResult method which returns a ResultUnit. This is a blocking call. {code} public class MWMaster extends MWApplicationMaster { private static final Log LOG = LogFactory.getLog(MWMaster.class); public static void main(String[] args) throws InterruptedException, ParseException, IOException, URISyntaxException { MWMaster curr = new MWMaster(); curr.initiate(args); curr.terminate(); } @Override public void manageWorkers() { addWorker(); addWorker(); for(int i = 0; i 100; i++) { WorkUnit curr = new WorkUnit(); curr.setData(i); addWork(curr); } for(int i = 0; i 100; i++) { try { ResultUnit curr = (ResultUnit) waitForResult(); LOG.info(Receiveing Result + curr.getData()); } catch (InterruptedException e) { e.printStackTrace(); } } killWorker(); killWorker(); } } {code} Currenly, I have not provided Client API for submission. The Client is basically a part of the framework, the code of this can be found in the MWClient class. Here is how the example application is to be launched. There are 4 required parameters, the MasterWorker Library Jar (--masterworkerlib) which contains the client code, the MasterWorker Application Jar
[jira] [Commented] (MAPREDUCE-3315) Master-Worker Application on YARN
[ https://issues.apache.org/jira/browse/MAPREDUCE-3315?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13244241#comment-13244241 ] Nikhil S. Ketkar commented on MAPREDUCE-3315: - I have a preliminary implementation done (as described above) and would like to submit a patch. Where should I place the implementation in the source hierarchy? There are 2 maven projects, firstly the Master-Worker framework part and second a very simple example application using the framework. Master-Worker Application on YARN - Key: MAPREDUCE-3315 URL: https://issues.apache.org/jira/browse/MAPREDUCE-3315 Project: Hadoop Map/Reduce Issue Type: New Feature Reporter: Sharad Agarwal Assignee: Sharad Agarwal Fix For: 0.24.0 Currently master worker scenarios are forced fit into Map-Reduce. Now with YARN, these can be first class and would benefit real/near realtime workloads and be more effective in using the cluster resources. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (MAPREDUCE-3315) Master-Worker Application on YARN
[ https://issues.apache.org/jira/browse/MAPREDUCE-3315?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13235534#comment-13235534 ] Sharad Agarwal commented on MAPREDUCE-3315: --- bq. Should I use Hadoop IPC or RMI Hadoop IPC bq. Should the Master be in the ApplicationManager or be run as a Container? For Master, you need to write a yarn ApplicationMaster (AM) see - http://hadoop.apache.org/common/docs/r0.23.0/hadoop-yarn/hadoop-yarn-site/WritingYarnApplications.html AM runs in one of the container on the cluster. Also it would be good to completely separate the user API (writing master-worker apps) and the runtime implementation clearly. Master-Worker Application on YARN - Key: MAPREDUCE-3315 URL: https://issues.apache.org/jira/browse/MAPREDUCE-3315 Project: Hadoop Map/Reduce Issue Type: New Feature Reporter: Sharad Agarwal Assignee: Sharad Agarwal Fix For: 0.24.0 Currently master worker scenarios are forced fit into Map-Reduce. Now with YARN, these can be first class and would benefit real/near realtime workloads and be more effective in using the cluster resources. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (MAPREDUCE-3315) Master-Worker Application on YARN
[ https://issues.apache.org/jira/browse/MAPREDUCE-3315?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13234229#comment-13234229 ] Nikhil S. Ketkar commented on MAPREDUCE-3315: - I have started some work on this issue and I wanted to describe the overall approach I am taking and get some feedback. Let me start by describing how an application will be written using Master-Worker. The pseudocode below illustrates the usage. {code} class WordCount { // Word count implementation using Master-Worker paradigm. // Master sends portions of the input file to workers // Worker builds a word count hash map (word - count) and sends it as a result unit // Master uses the results to update master dictionary class WorkUnit { // A list of words } class ResultUnit { // Map of word - count } class Master extends MasterRunnerWorkUnit, ResultUnit { public manageWorkers() { // Spawn a bunch of workers using spawnNewWorker(); // For each spawned worker spawnNewWorker() will return a WorkerReference, keep it around for bookkeeping // Read a file and create WorkUnits with a fixed number of lines to each workers // Assign WorkUnits to Workers using assignWork(), use the previously obtained WorkerReference // Wait for ResultUnits using waitForResult(); // Update master dictionary based on a received result unit // After work is done, kill workers using terminateWorker() } } class Worker extends WorkerRunnerWorkUnit, ResultUnit { public ResultUnit doWork(WorkUnit wu) { // Build a word count hash map (word - count) and sends it as a result unit } } } // User writes code to setup and launch job public static void main(String[] args) throws Exception { MWJobConf conf = new MWJobConf(WordCount.class); conf.setJobName(WordCount); conf.setMasterClass(Master.class); conf.setWorkerClass(Worker.class); conf.setWorkUnitClass(WorkUnit.class); conf.setResultUnitClass(ResultUnit.class); MWJobClient.runJob(conf); } } {code} Key functionality for the Master Worker will be implemented in the following classes. {code} class MasterRunnerW, R { // Spawn new Worker protected WorkerReference spawnNewWorker(); // Spawn new Workers protected ArrayListWorkerReference spawnNewWorkers(); // Assign work to any Worker, returns WorkerReference to whom it was assigned protected WorkerReference assignWork(WorkUnit wu); // Assign work to a specific Worker protected void assignWork(WorkerReference wf, WorkUnit wu); // Wait for result from any Worker. Blocking Call protected ResultUnit waitForResult(); // Wait for result from a specific worker. Blocking Call protected ResultUnit waitForResult(WorkerReference wf); // Is this specific worker alive? Blocking Call protected boolean isWorkerAlive(WorkerReference wf); // Get alive workers? Blocking Call protected ArrayListWorkerReference isWorkerAlive(WorkerReference wf); // Terminate a specific Worker protected void terminateWorker(WorkerReference wf); // To be implemented by user public manageWorkers() = 0; } class WorkerRunnerW, R { // To be implemented by user public ResultUnit doWork(WorkUnit wu) = 0; } class WorkUnitContainerW { // The framework passes around WorkUnitContainers which contain the user defined // WorkUnit and some additional bookkeeping information } class ResultUnitContainerR { // The framework passes around ResultUnitContainers which contain the user defined // ResultUnit and some additional bookkeeping information } class WorkerReference { // Uniquely identifies the Workers } {code} A few questions I have been thinking about are: # Should I use Hadoop IPC or RMI or something else? # Should the Master be in the ApplicationManager or be run as a Container? Master-Worker Application on YARN - Key: MAPREDUCE-3315 URL: https://issues.apache.org/jira/browse/MAPREDUCE-3315 Project: Hadoop Map/Reduce Issue Type: New Feature Reporter: Sharad Agarwal Assignee: Sharad Agarwal Fix For: 0.24.0 Currently master worker scenarios are forced fit into Map-Reduce. Now with YARN, these can be first class and would benefit real/near realtime workloads and be more effective in using the cluster resources. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (MAPREDUCE-3315) Master-Worker Application on YARN
[ https://issues.apache.org/jira/browse/MAPREDUCE-3315?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=13140059#comment-13140059 ] Sharad Agarwal commented on MAPREDUCE-3315: --- some thoughts: - AM decides the Tasks. - worker keep polling AM for getting the next Task instance. - should be able to dynamically increase or shutdown workers - have minWorkers, maxWorkers, keepAlive Master-Worker Application on YARN - Key: MAPREDUCE-3315 URL: https://issues.apache.org/jira/browse/MAPREDUCE-3315 Project: Hadoop Map/Reduce Issue Type: New Feature Reporter: Sharad Agarwal Assignee: Sharad Agarwal Fix For: 0.24.0 Currently master worker scenarios are forced fit into Map-Reduce. Now with YARN, these can be first class and would benefit real/near realtime workloads and be more effective in using the cluster resources. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira