Re: Remove Hadoop 1 support (Hadoop 2.2) for Spark 1.5?
Yeah so Steve, hopefully it's self evident, but that is a perfect example of the kind of annoying stuff we don't want to force users to deal with by forcing an upgrade to 2.X. Compare the pain from Spark users of trying to reason about what to do (and btw it seems like the answer is simply that there isn't a good answer). And that will be experienced by every Spark users who uses AWS and the Spark ec2 scripts, which are extremely popular. Is this pain, in aggregate, more than our cost of having a few patches to deal with runtime reflection stuff to make things work with Hadoop 1? My feeling is that it's much more efficient for us as the Spark maintainers to pay this cost rather than to force a lot of our users to deal with painful upgrades. On Sat, Jun 13, 2015 at 1:39 AM, Steve Loughran ste...@hortonworks.com wrote: On 12 Jun 2015, at 17:12, Patrick Wendell pwend...@gmail.com wrote: For instance at Databricks we use the FileSystem library for talking to S3... every time we've tried to upgrade to Hadoop 2.X there have been significant regressions in performance and we've had to downgrade. That's purely anecdotal, but I think you have people out there using the Hadoop 1 bindings for whom upgrade would be a pain. ah s3n. The unloved orphan FS, which has been fairly neglected as being non-strategic to anyone but Amazon, who have a private fork. s3n broke in hadopo 2.4 where the upgraded Jets3t went in with some patch which swallowed exceptions (nobody should ever do that) and as result would NPE on a seek(0) of a file of length(0). HADOOP-10457. Fixed in Hadoop 2.5 Hadoop 2.6 has left S3n on maintenance out of fear of breaking more things, future work is in s3a:,, which switched to the amazon awstoolkit JAR and moved the implementation to hadoop-aws JAR. S3a promises: speed, partitioned upload, better auth. But: it's not ready for serious use in Hadoop 2.6, so don't try. You need the Hadoop 2.7 patches, which are in ASF Hadoop 2.7, will be in HDP2.3, and have been picked up in CDH5.3. (HADOOP-11571). For Spark, the fact that the block size is being returned as 0 in getFileStatus() could be the killer. Future work is going to improve performance and scale ( HADOOP-11694 ) Now, if spark is finding problems with s3a performance, tests for this would be great -complaints on JIRAs too. There's not enough functional testing of analytics workloads against the object stores, especially s3 and swift. If someone volunteers to add some optional test module for object store testing, I'll help review it and suggest some tests to generate stress That can be done without the leap to Hadoop 2 —though the proposed HADOOP-9565 work allowing object stores to declare that they are and publish some of their consistency and atomicity semantics will be Hadoop 2.8+. If you want your output committers to recognise when the destination is an eventually constitent object store with O(n) directory rename and delete, that's where the code will be. - To unsubscribe, e-mail: dev-unsubscr...@spark.apache.org For additional commands, e-mail: dev-h...@spark.apache.org
Re: Remove Hadoop 1 support (Hadoop 2.2) for Spark 1.5?
On 12 Jun 2015, at 17:12, Patrick Wendell pwend...@gmail.com wrote: For instance at Databricks we use the FileSystem library for talking to S3... every time we've tried to upgrade to Hadoop 2.X there have been significant regressions in performance and we've had to downgrade. That's purely anecdotal, but I think you have people out there using the Hadoop 1 bindings for whom upgrade would be a pain. ah s3n. The unloved orphan FS, which has been fairly neglected as being non-strategic to anyone but Amazon, who have a private fork. s3n broke in hadopo 2.4 where the upgraded Jets3t went in with some patch which swallowed exceptions (nobody should ever do that) and as result would NPE on a seek(0) of a file of length(0). HADOOP-10457. Fixed in Hadoop 2.5 Hadoop 2.6 has left S3n on maintenance out of fear of breaking more things, future work is in s3a:,, which switched to the amazon awstoolkit JAR and moved the implementation to hadoop-aws JAR. S3a promises: speed, partitioned upload, better auth. But: it's not ready for serious use in Hadoop 2.6, so don't try. You need the Hadoop 2.7 patches, which are in ASF Hadoop 2.7, will be in HDP2.3, and have been picked up in CDH5.3. (HADOOP-11571). For Spark, the fact that the block size is being returned as 0 in getFileStatus() could be the killer. Future work is going to improve performance and scale ( HADOOP-11694 ) Now, if spark is finding problems with s3a performance, tests for this would be great -complaints on JIRAs too. There's not enough functional testing of analytics workloads against the object stores, especially s3 and swift. If someone volunteers to add some optional test module for object store testing, I'll help review it and suggest some tests to generate stress That can be done without the leap to Hadoop 2 —though the proposed HADOOP-9565 work allowing object stores to declare that they are and publish some of their consistency and atomicity semantics will be Hadoop 2.8+. If you want your output committers to recognise when the destination is an eventually constitent object store with O(n) directory rename and delete, that's where the code will be.
Re: Remove Hadoop 1 support (Hadoop 2.2) for Spark 1.5?
+1 for 2.2+ Not only are the APis in Hadoop 2 better, there's more people testing Hadoop 2.x spark, and bugs in Hadoop itself being fixed. (usual disclaimers, I work off branch-2.7 snapshots I build nightly, etc) On 12 Jun 2015, at 11:09, Sean Owen so...@cloudera.com wrote: How does the idea of removing support for Hadoop 1.x for Spark 1.5 strike everyone? Really, I mean, Hadoop 2.2, as 2.2 seems to me more consistent with the modern 2.x line than 2.1 or 2.0. The arguments against are simply, well, someone out there might be using these versions. The arguments for are just simplification -- fewer gotchas in trying to keep supporting older Hadoop, of which we've seen several lately. We get to chop out a little bit of shim code and update to use some non-deprecated APIs. Along with removing support for Java 6, it might be a reasonable time to also draw a line under older Hadoop too. I'm just gauging feeling now: for, against, indifferent? I favor it, but would not push hard on it if there are objections. - To unsubscribe, e-mail: dev-unsubscr...@spark.apache.org For additional commands, e-mail: dev-h...@spark.apache.org - To unsubscribe, e-mail: dev-unsubscr...@spark.apache.org For additional commands, e-mail: dev-h...@spark.apache.org
Re: Remove Hadoop 1 support (Hadoop 2.2) for Spark 1.5?
I feel this is quite different from the Java 6 decision and personally I don't see sufficient cause to do it. I would like to understand though Sean - what is the proposal exactly? Hadoop 2 itself supports all of the Hadoop 1 API's, so things like removing the Hadoop 1 variant of sc.hadoopFile, etc, I don't think that makes much sense since so many libraries still use those API's. For YARN support, we already don't support Hadoop 1. So I'll assume what you mean is to prevent or stop supporting from linking against the Hadoop 1 filesystem binaries at runtime (is that right?). The main reason I'd push back is that I do think there are still people running the older versions. For instance at Databricks we use the FileSystem library for talking to S3... every time we've tried to upgrade to Hadoop 2.X there have been significant regressions in performance and we've had to downgrade. That's purely anecdotal, but I think you have people out there using the Hadoop 1 bindings for whom upgrade would be a pain. In terms of our maintenance cost, to me the much bigger cost for us IMO is dealing with differences between e.g. 2.2, 2.4, and 2.6 where major new API's were added. In comparison the Hadoop 1 vs 2 seems fairly low with just a few bugs cropping up here and there. So unlike Java 6 where you have a critical mass of maintenance issues, security issues, etc, I just don't see as compelling a cost here. To me the framework for deciding about these upgrades is the maintenance cost vs the inconvenience for users. - Patrick On Fri, Jun 12, 2015 at 8:45 AM, Nicholas Chammas nicholas.cham...@gmail.com wrote: I'm personally in favor, but I don't have a sense of how many people still rely on Hadoop 1. Nick 2015년 6월 12일 (금) 오전 9:13, Steve Loughran ste...@hortonworks.com님이 작성: +1 for 2.2+ Not only are the APis in Hadoop 2 better, there's more people testing Hadoop 2.x spark, and bugs in Hadoop itself being fixed. (usual disclaimers, I work off branch-2.7 snapshots I build nightly, etc) On 12 Jun 2015, at 11:09, Sean Owen so...@cloudera.com wrote: How does the idea of removing support for Hadoop 1.x for Spark 1.5 strike everyone? Really, I mean, Hadoop 2.2, as 2.2 seems to me more consistent with the modern 2.x line than 2.1 or 2.0. The arguments against are simply, well, someone out there might be using these versions. The arguments for are just simplification -- fewer gotchas in trying to keep supporting older Hadoop, of which we've seen several lately. We get to chop out a little bit of shim code and update to use some non-deprecated APIs. Along with removing support for Java 6, it might be a reasonable time to also draw a line under older Hadoop too. I'm just gauging feeling now: for, against, indifferent? I favor it, but would not push hard on it if there are objections. - To unsubscribe, e-mail: dev-unsubscr...@spark.apache.org For additional commands, e-mail: dev-h...@spark.apache.org - To unsubscribe, e-mail: dev-unsubscr...@spark.apache.org For additional commands, e-mail: dev-h...@spark.apache.org - To unsubscribe, e-mail: dev-unsubscr...@spark.apache.org For additional commands, e-mail: dev-h...@spark.apache.org
Re: Remove Hadoop 1 support (Hadoop 2.2) for Spark 1.5?
+1 for Hadoop 2.2+ On Fri, Jun 12, 2015 at 8:45 AM, Nicholas Chammas nicholas.cham...@gmail.com wrote: I'm personally in favor, but I don't have a sense of how many people still rely on Hadoop 1. Nick 2015년 6월 12일 (금) 오전 9:13, Steve Loughran ste...@hortonworks.com님이 작성: +1 for 2.2+ Not only are the APis in Hadoop 2 better, there's more people testing Hadoop 2.x spark, and bugs in Hadoop itself being fixed. (usual disclaimers, I work off branch-2.7 snapshots I build nightly, etc) On 12 Jun 2015, at 11:09, Sean Owen so...@cloudera.com wrote: How does the idea of removing support for Hadoop 1.x for Spark 1.5 strike everyone? Really, I mean, Hadoop 2.2, as 2.2 seems to me more consistent with the modern 2.x line than 2.1 or 2.0. The arguments against are simply, well, someone out there might be using these versions. The arguments for are just simplification -- fewer gotchas in trying to keep supporting older Hadoop, of which we've seen several lately. We get to chop out a little bit of shim code and update to use some non-deprecated APIs. Along with removing support for Java 6, it might be a reasonable time to also draw a line under older Hadoop too. I'm just gauging feeling now: for, against, indifferent? I favor it, but would not push hard on it if there are objections. - To unsubscribe, e-mail: dev-unsubscr...@spark.apache.org For additional commands, e-mail: dev-h...@spark.apache.org - To unsubscribe, e-mail: dev-unsubscr...@spark.apache.org For additional commands, e-mail: dev-h...@spark.apache.org
Re: Remove Hadoop 1 support (Hadoop 2.2) for Spark 1.5?
My 2 cents: The biggest reason from my view for keeping Hadoop 1 support was that our EC2 scripts which launch an environment for benchmarking / testing / research only supported Hadoop 1 variants till very recently. We did add Hadoop 2.4 support a few weeks back but that it is still not the default option. My concern is that people have higher level projects which are linked to Hadoop 1.0.4 + Spark, because that is the default environment on EC2, and that users will be surprised when these applications stop working in Spark 1.5. I guess we could announce more widely and write transition guides, but if the cost of supporting Hadoop1 is low enough, I'd vote to keeping it. Thanks Shivaram On Fri, Jun 12, 2015 at 9:11 AM, Ram Sriharsha sriharsha@gmail.com wrote: +1 for Hadoop 2.2+ On Fri, Jun 12, 2015 at 8:45 AM, Nicholas Chammas nicholas.cham...@gmail.com wrote: I'm personally in favor, but I don't have a sense of how many people still rely on Hadoop 1. Nick 2015년 6월 12일 (금) 오전 9:13, Steve Loughran ste...@hortonworks.com님이 작성: +1 for 2.2+ Not only are the APis in Hadoop 2 better, there's more people testing Hadoop 2.x spark, and bugs in Hadoop itself being fixed. (usual disclaimers, I work off branch-2.7 snapshots I build nightly, etc) On 12 Jun 2015, at 11:09, Sean Owen so...@cloudera.com wrote: How does the idea of removing support for Hadoop 1.x for Spark 1.5 strike everyone? Really, I mean, Hadoop 2.2, as 2.2 seems to me more consistent with the modern 2.x line than 2.1 or 2.0. The arguments against are simply, well, someone out there might be using these versions. The arguments for are just simplification -- fewer gotchas in trying to keep supporting older Hadoop, of which we've seen several lately. We get to chop out a little bit of shim code and update to use some non-deprecated APIs. Along with removing support for Java 6, it might be a reasonable time to also draw a line under older Hadoop too. I'm just gauging feeling now: for, against, indifferent? I favor it, but would not push hard on it if there are objections. - To unsubscribe, e-mail: dev-unsubscr...@spark.apache.org For additional commands, e-mail: dev-h...@spark.apache.org - To unsubscribe, e-mail: dev-unsubscr...@spark.apache.org For additional commands, e-mail: dev-h...@spark.apache.org
Re: Remove Hadoop 1 support (Hadoop 2.2) for Spark 1.5?
I'm personally in favor, but I don't have a sense of how many people still rely on Hadoop 1. Nick 2015년 6월 12일 (금) 오전 9:13, Steve Loughran ste...@hortonworks.com님이 작성: +1 for 2.2+ Not only are the APis in Hadoop 2 better, there's more people testing Hadoop 2.x spark, and bugs in Hadoop itself being fixed. (usual disclaimers, I work off branch-2.7 snapshots I build nightly, etc) On 12 Jun 2015, at 11:09, Sean Owen so...@cloudera.com wrote: How does the idea of removing support for Hadoop 1.x for Spark 1.5 strike everyone? Really, I mean, Hadoop 2.2, as 2.2 seems to me more consistent with the modern 2.x line than 2.1 or 2.0. The arguments against are simply, well, someone out there might be using these versions. The arguments for are just simplification -- fewer gotchas in trying to keep supporting older Hadoop, of which we've seen several lately. We get to chop out a little bit of shim code and update to use some non-deprecated APIs. Along with removing support for Java 6, it might be a reasonable time to also draw a line under older Hadoop too. I'm just gauging feeling now: for, against, indifferent? I favor it, but would not push hard on it if there are objections. - To unsubscribe, e-mail: dev-unsubscr...@spark.apache.org For additional commands, e-mail: dev-h...@spark.apache.org - To unsubscribe, e-mail: dev-unsubscr...@spark.apache.org For additional commands, e-mail: dev-h...@spark.apache.org
Re: Remove Hadoop 1 support (Hadoop 2.2) for Spark 1.5?
On Fri, Jun 12, 2015 at 5:12 PM, Patrick Wendell pwend...@gmail.com wrote: I would like to understand though Sean - what is the proposal exactly? Hadoop 2 itself supports all of the Hadoop 1 API's, so things like removing the Hadoop 1 variant of sc.hadoopFile, etc, I don't think Not entirely; you can see some binary incompatibilities that have bitten recently. A Hadoop 1 program does not in general work on Hadoop 2 because of this. Part of my thinking is that I'm not clear Hadoop 1.x, and 2.0.x, fully works anymore anyway. See for example SPARK-8057 recently. I recall similar problems with Hadoop 2.0.x-era releases and the Spark build for that which is basically the 'cdh4' build. So one benefit is skipping whatever work would be needed to continue to fix this up, and, the argument is there may be less loss of functionality than it seems. The other is being able to use later APIs. This much is a little minor. The main reason I'd push back is that I do think there are still people running the older versions. For instance at Databricks we use the FileSystem library for talking to S3... every time we've tried to upgrade to Hadoop 2.X there have been significant regressions in performance and we've had to downgrade. That's purely anecdotal, but I think you have people out there using the Hadoop 1 bindings for whom upgrade would be a pain. Yeah, that's the question. Is anyone out there using 1.x? More anecdotes wanted. That might be the most interesting question. No CDH customers would have been for a long while now, for example. (Still a small number of CDH 4 customers out there though, and that's 2.0.x or so, but that's a gray area.) Is the S3 library thing really related to Hadoop 1.x? that comes from jets3t and that's independent. In terms of our maintenance cost, to me the much bigger cost for us IMO is dealing with differences between e.g. 2.2, 2.4, and 2.6 where major new API's were added. In comparison the Hadoop 1 vs 2 seems Really? I'd say the opposite. No APIs that are only in 2.2, let alone only in a later version, can be in use now, right? 1.x wouldn't work at all then. I don't know of any binary incompatibilities of the type between 1.x and 2.x, which we have had to shim to make work. In both cases dependencies have to be harmonized here and there, yes. That won't change. - To unsubscribe, e-mail: dev-unsubscr...@spark.apache.org For additional commands, e-mail: dev-h...@spark.apache.org
Re: Remove Hadoop 1 support (Hadoop 2.2) for Spark 1.5?
I don't imagine that can be guaranteed to be supported anyway... the 0.x branch has never necessarily worked with Spark, even if it might happen to. Is this really something you would veto for everyone because of your deployment? On Fri, Jun 12, 2015 at 7:18 PM, Thomas Dudziak tom...@gmail.com wrote: -1 to this, we use it with an old Hadoop version (well, a fork of an old version, 0.23). That being said, if there were a nice developer api that separates Spark from Hadoop (or rather, two APIs, one for scheduling and one for HDFS), then we'd be happy to maintain our own plugins for those. cheers, Tom - To unsubscribe, e-mail: dev-unsubscr...@spark.apache.org For additional commands, e-mail: dev-h...@spark.apache.org
Re: Remove Hadoop 1 support (Hadoop 2.2) for Spark 1.5?
I don't like the idea of removing Hadoop 1 unless it becomes a significant maintenance burden, which I don't think it is. You'll always be surprised how many people use old software, even though various companies may no longer support them. With Hadoop 2 in particular, I may be misremembering, but I believe that the experience on Windows is considerably worse because it requires these shell scripts to set permissions that it won't find if you just download Spark. That would be one reason to keep Hadoop 1 in the default build. But I could be wrong, it's been a while since I tried Windows. Matei On Jun 12, 2015, at 11:21 AM, Sean Owen so...@cloudera.com wrote: I don't imagine that can be guaranteed to be supported anyway... the 0.x branch has never necessarily worked with Spark, even if it might happen to. Is this really something you would veto for everyone because of your deployment? On Fri, Jun 12, 2015 at 7:18 PM, Thomas Dudziak tom...@gmail.com wrote: -1 to this, we use it with an old Hadoop version (well, a fork of an old version, 0.23). That being said, if there were a nice developer api that separates Spark from Hadoop (or rather, two APIs, one for scheduling and one for HDFS), then we'd be happy to maintain our own plugins for those. cheers, Tom - To unsubscribe, e-mail: dev-unsubscr...@spark.apache.org For additional commands, e-mail: dev-h...@spark.apache.org - To unsubscribe, e-mail: dev-unsubscr...@spark.apache.org For additional commands, e-mail: dev-h...@spark.apache.org
Re: Remove Hadoop 1 support (Hadoop 2.2) for Spark 1.5?
0.23 (and hive 0.12) code base in Spark works well from our perspective, so not sure what you are referring to. As I said, I'm happy to maintain my own plugins but as it stands there is no sane way to do so in Spark because there is no clear separation/developer APIs for these. cheers, Tom On Fri, Jun 12, 2015 at 11:21 AM, Sean Owen so...@cloudera.com wrote: I don't imagine that can be guaranteed to be supported anyway... the 0.x branch has never necessarily worked with Spark, even if it might happen to. Is this really something you would veto for everyone because of your deployment? On Fri, Jun 12, 2015 at 7:18 PM, Thomas Dudziak tom...@gmail.com wrote: -1 to this, we use it with an old Hadoop version (well, a fork of an old version, 0.23). That being said, if there were a nice developer api that separates Spark from Hadoop (or rather, two APIs, one for scheduling and one for HDFS), then we'd be happy to maintain our own plugins for those. cheers, Tom
Re: Remove Hadoop 1 support (Hadoop 2.2) for Spark 1.5?
-1 to this, we use it with an old Hadoop version (well, a fork of an old version, 0.23). That being said, if there were a nice developer api that separates Spark from Hadoop (or rather, two APIs, one for scheduling and one for HDFS), then we'd be happy to maintain our own plugins for those. cheers, Tom On Fri, Jun 12, 2015 at 9:42 AM, Sean Owen so...@cloudera.com wrote: On Fri, Jun 12, 2015 at 5:12 PM, Patrick Wendell pwend...@gmail.com wrote: I would like to understand though Sean - what is the proposal exactly? Hadoop 2 itself supports all of the Hadoop 1 API's, so things like removing the Hadoop 1 variant of sc.hadoopFile, etc, I don't think Not entirely; you can see some binary incompatibilities that have bitten recently. A Hadoop 1 program does not in general work on Hadoop 2 because of this. Part of my thinking is that I'm not clear Hadoop 1.x, and 2.0.x, fully works anymore anyway. See for example SPARK-8057 recently. I recall similar problems with Hadoop 2.0.x-era releases and the Spark build for that which is basically the 'cdh4' build. So one benefit is skipping whatever work would be needed to continue to fix this up, and, the argument is there may be less loss of functionality than it seems. The other is being able to use later APIs. This much is a little minor. The main reason I'd push back is that I do think there are still people running the older versions. For instance at Databricks we use the FileSystem library for talking to S3... every time we've tried to upgrade to Hadoop 2.X there have been significant regressions in performance and we've had to downgrade. That's purely anecdotal, but I think you have people out there using the Hadoop 1 bindings for whom upgrade would be a pain. Yeah, that's the question. Is anyone out there using 1.x? More anecdotes wanted. That might be the most interesting question. No CDH customers would have been for a long while now, for example. (Still a small number of CDH 4 customers out there though, and that's 2.0.x or so, but that's a gray area.) Is the S3 library thing really related to Hadoop 1.x? that comes from jets3t and that's independent. In terms of our maintenance cost, to me the much bigger cost for us IMO is dealing with differences between e.g. 2.2, 2.4, and 2.6 where major new API's were added. In comparison the Hadoop 1 vs 2 seems Really? I'd say the opposite. No APIs that are only in 2.2, let alone only in a later version, can be in use now, right? 1.x wouldn't work at all then. I don't know of any binary incompatibilities of the type between 1.x and 2.x, which we have had to shim to make work. In both cases dependencies have to be harmonized here and there, yes. That won't change. - To unsubscribe, e-mail: dev-unsubscr...@spark.apache.org For additional commands, e-mail: dev-h...@spark.apache.org
