Re: Local file system to access hdfs blocks
I am not sure this is what you want but you can try this shell command: find [DATANODE_DIR] -name [blockname] On Tue, Aug 26, 2014 at 6:42 AM, Demai Ni wrote: > Hi, folks, > > New in this area. Hopefully to get a couple pointers. > > I am using Centos and have Hadoop set up using cdh5.1(Hadoop 2.3) > > I am wondering whether there is a interface to get each hdfs block > information in the term of local file system. > > For example, I can use "Hadoop fsck /tmp/test.txt -files -blocks -racks" > to get blockID and its replica on the nodes, such as: repl =3[ > /rack/hdfs01, /rack/hdfs02...] > > With such info, is there a way to > 1) login to hfds01, and read the block directly at local file system level? > > > Thanks > > Demai on the run -- Regards, *Stanley Shi,*
Re: Local file system to access hdfs blocks
Hi, Stanley, Many thanks. Your method works. For now, I can have two steps approach: 1) getFileBlockLocations to grab hdfs BlockLocation[] 2) use local file system call(like find command) to match the block to files on local file system . Maybe there is an existing Hadoop API to return such info in already? Demai on the run On Aug 26, 2014, at 9:14 PM, Stanley Shi wrote: > I am not sure this is what you want but you can try this shell command: > > find [DATANODE_DIR] -name [blockname] > > > On Tue, Aug 26, 2014 at 6:42 AM, Demai Ni wrote: >> Hi, folks, >> >> New in this area. Hopefully to get a couple pointers. >> >> I am using Centos and have Hadoop set up using cdh5.1(Hadoop 2.3) >> >> I am wondering whether there is a interface to get each hdfs block >> information in the term of local file system. >> >> For example, I can use "Hadoop fsck /tmp/test.txt -files -blocks -racks" to >> get blockID and its replica on the nodes, such as: repl =3[ /rack/hdfs01, >> /rack/hdfs02...] >> >> With such info, is there a way to >> 1) login to hfds01, and read the block directly at local file system level? >> >> >> Thanks >> >> Demai on the run > > > > -- > Regards, > Stanley Shi, >
Re: Local file system to access hdfs blocks
Hi Demai, You can use fsck utility like the following: hadoop fsck /path/to/your/hdfs/file -files -blocks -locations -racks This will display all the information you need about the blocks of your file. Hope it helps. Yehia On 27 August 2014 20:18, Demai Ni wrote: > Hi, Stanley, > > Many thanks. Your method works. For now, I can have two steps approach: > 1) getFileBlockLocations to grab hdfs BlockLocation[] > 2) use local file system call(like find command) to match the block to > files on local file system . > > Maybe there is an existing Hadoop API to return such info in already? > > Demai on the run > > On Aug 26, 2014, at 9:14 PM, Stanley Shi wrote: > > I am not sure this is what you want but you can try this shell command: > > find [DATANODE_DIR] -name [blockname] > > > On Tue, Aug 26, 2014 at 6:42 AM, Demai Ni wrote: > >> Hi, folks, >> >> New in this area. Hopefully to get a couple pointers. >> >> I am using Centos and have Hadoop set up using cdh5.1(Hadoop 2.3) >> >> I am wondering whether there is a interface to get each hdfs block >> information in the term of local file system. >> >> For example, I can use "Hadoop fsck /tmp/test.txt -files -blocks -racks" >> to get blockID and its replica on the nodes, such as: repl =3[ >> /rack/hdfs01, /rack/hdfs02...] >> >> With such info, is there a way to >> 1) login to hfds01, and read the block directly at local file system >> level? >> >> >> Thanks >> >> Demai on the run > > > > > -- > Regards, > *Stanley Shi,* > >
Re: Local file system to access hdfs blocks
Hi Demai, Sorry, I missed that you are already tried this out. I think you can construct the block location on the local file system if you have the block pool id and the block id. If you are using cloudera distribution, the default location is under /dfs/dn ( the value of dfs.data.dir, dfs.datanode.data.dir configuration keys). Thanks Yehia On 27 August 2014 21:20, Yehia Elshater wrote: > Hi Demai, > > You can use fsck utility like the following: > > hadoop fsck /path/to/your/hdfs/file -files -blocks -locations -racks > > This will display all the information you need about the blocks of your > file. > > Hope it helps. > Yehia > > > On 27 August 2014 20:18, Demai Ni wrote: > >> Hi, Stanley, >> >> Many thanks. Your method works. For now, I can have two steps approach: >> 1) getFileBlockLocations to grab hdfs BlockLocation[] >> 2) use local file system call(like find command) to match the block to >> files on local file system . >> >> Maybe there is an existing Hadoop API to return such info in already? >> >> Demai on the run >> >> On Aug 26, 2014, at 9:14 PM, Stanley Shi wrote: >> >> I am not sure this is what you want but you can try this shell command: >> >> find [DATANODE_DIR] -name [blockname] >> >> >> On Tue, Aug 26, 2014 at 6:42 AM, Demai Ni wrote: >> >>> Hi, folks, >>> >>> New in this area. Hopefully to get a couple pointers. >>> >>> I am using Centos and have Hadoop set up using cdh5.1(Hadoop 2.3) >>> >>> I am wondering whether there is a interface to get each hdfs block >>> information in the term of local file system. >>> >>> For example, I can use "Hadoop fsck /tmp/test.txt -files -blocks -racks" >>> to get blockID and its replica on the nodes, such as: repl =3[ >>> /rack/hdfs01, /rack/hdfs02...] >>> >>> With such info, is there a way to >>> 1) login to hfds01, and read the block directly at local file system >>> level? >>> >>> >>> Thanks >>> >>> Demai on the run >> >> >> >> >> -- >> Regards, >> *Stanley Shi,* >> >> >
Re: Local file system to access hdfs blocks
Yehia, No problem at all. I really appreciate your willingness to help. Yeah. now I am able to get such information through two steps, and the first step will be either hadoop fsck or getFileBlockLocations(). and then search the local filesystem, my cluster is using the default from CDH, which is /dfs/dn I would like to it programmatically, so wondering whether someone already done it? or maybe better a hadoop API call already implemented for this exact purpose Demai On Wed, Aug 27, 2014 at 7:58 PM, Yehia Elshater wrote: > Hi Demai, > > Sorry, I missed that you are already tried this out. I think you can > construct the block location on the local file system if you have the block > pool id and the block id. If you are using cloudera distribution, the > default location is under /dfs/dn ( the value of dfs.data.dir, > dfs.datanode.data.dir configuration keys). > > Thanks > Yehia > > > On 27 August 2014 21:20, Yehia Elshater wrote: > >> Hi Demai, >> >> You can use fsck utility like the following: >> >> hadoop fsck /path/to/your/hdfs/file -files -blocks -locations -racks >> >> This will display all the information you need about the blocks of your >> file. >> >> Hope it helps. >> Yehia >> >> >> On 27 August 2014 20:18, Demai Ni wrote: >> >>> Hi, Stanley, >>> >>> Many thanks. Your method works. For now, I can have two steps approach: >>> 1) getFileBlockLocations to grab hdfs BlockLocation[] >>> 2) use local file system call(like find command) to match the block to >>> files on local file system . >>> >>> Maybe there is an existing Hadoop API to return such info in already? >>> >>> Demai on the run >>> >>> On Aug 26, 2014, at 9:14 PM, Stanley Shi wrote: >>> >>> I am not sure this is what you want but you can try this shell command: >>> >>> find [DATANODE_DIR] -name [blockname] >>> >>> >>> On Tue, Aug 26, 2014 at 6:42 AM, Demai Ni wrote: >>> Hi, folks, New in this area. Hopefully to get a couple pointers. I am using Centos and have Hadoop set up using cdh5.1(Hadoop 2.3) I am wondering whether there is a interface to get each hdfs block information in the term of local file system. For example, I can use "Hadoop fsck /tmp/test.txt -files -blocks -racks" to get blockID and its replica on the nodes, such as: repl =3[ /rack/hdfs01, /rack/hdfs02...] With such info, is there a way to 1) login to hfds01, and read the block directly at local file system level? Thanks Demai on the run >>> >>> >>> >>> >>> -- >>> Regards, >>> *Stanley Shi,* >>> >>> >> >
Re: Local file system to access hdfs blocks
As far as I know, there's no combination of hadoop API can do that. You can easily get the location of the block (on which DN), but there's no way to get the local address of that block file. On Thu, Aug 28, 2014 at 11:54 AM, Demai Ni wrote: > Yehia, > > No problem at all. I really appreciate your willingness to help. Yeah. now > I am able to get such information through two steps, and the first step > will be either hadoop fsck or getFileBlockLocations(). and then search > the local filesystem, my cluster is using the default from CDH, which is > /dfs/dn > > I would like to it programmatically, so wondering whether someone already > done it? or maybe better a hadoop API call already implemented for this > exact purpose > > Demai > > > On Wed, Aug 27, 2014 at 7:58 PM, Yehia Elshater > wrote: > >> Hi Demai, >> >> Sorry, I missed that you are already tried this out. I think you can >> construct the block location on the local file system if you have the block >> pool id and the block id. If you are using cloudera distribution, the >> default location is under /dfs/dn ( the value of dfs.data.dir, >> dfs.datanode.data.dir configuration keys). >> >> Thanks >> Yehia >> >> >> On 27 August 2014 21:20, Yehia Elshater wrote: >> >>> Hi Demai, >>> >>> You can use fsck utility like the following: >>> >>> hadoop fsck /path/to/your/hdfs/file -files -blocks -locations -racks >>> >>> This will display all the information you need about the blocks of your >>> file. >>> >>> Hope it helps. >>> Yehia >>> >>> >>> On 27 August 2014 20:18, Demai Ni wrote: >>> Hi, Stanley, Many thanks. Your method works. For now, I can have two steps approach: 1) getFileBlockLocations to grab hdfs BlockLocation[] 2) use local file system call(like find command) to match the block to files on local file system . Maybe there is an existing Hadoop API to return such info in already? Demai on the run On Aug 26, 2014, at 9:14 PM, Stanley Shi wrote: I am not sure this is what you want but you can try this shell command: find [DATANODE_DIR] -name [blockname] On Tue, Aug 26, 2014 at 6:42 AM, Demai Ni wrote: > Hi, folks, > > New in this area. Hopefully to get a couple pointers. > > I am using Centos and have Hadoop set up using cdh5.1(Hadoop 2.3) > > I am wondering whether there is a interface to get each hdfs block > information in the term of local file system. > > For example, I can use "Hadoop fsck /tmp/test.txt -files -blocks > -racks" to get blockID and its replica on the nodes, such as: repl =3[ > /rack/hdfs01, /rack/hdfs02...] > > With such info, is there a way to > 1) login to hfds01, and read the block directly at local file system > level? > > > Thanks > > Demai on the run -- Regards, *Stanley Shi,* >>> >> > -- Regards, *Stanley Shi,*
Re: Local file system to access hdfs blocks
Stanley and all, thanks. I will write a client application to explore this path. A quick question again. Using the fsck command, I can retrieve all the necessary info $ hadoop fsck /tmp/list2.txt -files -blocks -racks . *BP-13-7914115-10.122.195.197-14909166276345:blk_1073742025* len=8 repl=2 [/default/10.122.195.198:50010, /default/10.122.195.196:50010] However, using getFileBlockLocations(), I can't get the block name/id info, such as *BP-13-7914115-10.122.195.197-14909166276345:blk_1073742025*seem the BlockLocation don't provide the public info here. http://hadoop.apache.org/docs/current/api/org/apache/hadoop/fs/BlockLocation.html is there another entry point? somethinig fsck is using? thanks Demai On Wed, Aug 27, 2014 at 11:09 PM, Stanley Shi wrote: > As far as I know, there's no combination of hadoop API can do that. > You can easily get the location of the block (on which DN), but there's no > way to get the local address of that block file. > > > > On Thu, Aug 28, 2014 at 11:54 AM, Demai Ni wrote: > >> Yehia, >> >> No problem at all. I really appreciate your willingness to help. Yeah. >> now I am able to get such information through two steps, and the first step >> will be either hadoop fsck or getFileBlockLocations(). and then search >> the local filesystem, my cluster is using the default from CDH, which is >> /dfs/dn >> >> I would like to it programmatically, so wondering whether someone already >> done it? or maybe better a hadoop API call already implemented for this >> exact purpose >> >> Demai >> >> >> On Wed, Aug 27, 2014 at 7:58 PM, Yehia Elshater >> wrote: >> >>> Hi Demai, >>> >>> Sorry, I missed that you are already tried this out. I think you can >>> construct the block location on the local file system if you have the block >>> pool id and the block id. If you are using cloudera distribution, the >>> default location is under /dfs/dn ( the value of dfs.data.dir, >>> dfs.datanode.data.dir configuration keys). >>> >>> Thanks >>> Yehia >>> >>> >>> On 27 August 2014 21:20, Yehia Elshater wrote: >>> Hi Demai, You can use fsck utility like the following: hadoop fsck /path/to/your/hdfs/file -files -blocks -locations -racks This will display all the information you need about the blocks of your file. Hope it helps. Yehia On 27 August 2014 20:18, Demai Ni wrote: > Hi, Stanley, > > Many thanks. Your method works. For now, I can have two steps approach: > 1) getFileBlockLocations to grab hdfs BlockLocation[] > 2) use local file system call(like find command) to match the block to > files on local file system . > > Maybe there is an existing Hadoop API to return such info in already? > > Demai on the run > > On Aug 26, 2014, at 9:14 PM, Stanley Shi wrote: > > I am not sure this is what you want but you can try this shell command: > > find [DATANODE_DIR] -name [blockname] > > > On Tue, Aug 26, 2014 at 6:42 AM, Demai Ni wrote: > >> Hi, folks, >> >> New in this area. Hopefully to get a couple pointers. >> >> I am using Centos and have Hadoop set up using cdh5.1(Hadoop 2.3) >> >> I am wondering whether there is a interface to get each hdfs block >> information in the term of local file system. >> >> For example, I can use "Hadoop fsck /tmp/test.txt -files -blocks >> -racks" to get blockID and its replica on the nodes, such as: repl =3[ >> /rack/hdfs01, /rack/hdfs02...] >> >> With such info, is there a way to >> 1) login to hfds01, and read the block directly at local file system >> level? >> >> >> Thanks >> >> Demai on the run > > > > > -- > Regards, > *Stanley Shi,* > > >>> >> > > > -- > Regards, > *Stanley Shi,* > >
Re: Local file system to access hdfs blocks
*BP-13-7914115-10.122.195.197-14909166276345 is the blockpool information* *blk_1073742025 <1073742025> is the block name;* *these names are "private" to teh HDFS system and user should not use them, right?* *But if you really want ot know this, you can check the fsck code to see whether they are available;* On Fri, Aug 29, 2014 at 8:13 AM, Demai Ni wrote: > Stanley and all, > > thanks. I will write a client application to explore this path. A quick > question again. > Using the fsck command, I can retrieve all the necessary info > $ hadoop fsck /tmp/list2.txt -files -blocks -racks > . > *BP-13-7914115-10.122.195.197-14909166276345:blk_1073742025 <1073742025>* > len=8 repl=2 > [/default/10.122.195.198:50010, /default/10.122.195.196:50010] > > However, using getFileBlockLocations(), I can't get the block name/id > info, such as > *BP-13-7914115-10.122.195.197-14909166276345:blk_1073742025 <1073742025> *seem > the BlockLocation don't provide the public info here. > http://hadoop.apache.org/docs/current/api/org/apache/hadoop/fs/BlockLocation.html > > is there another entry point? somethinig fsck is using? thanks > > Demai > > > > > On Wed, Aug 27, 2014 at 11:09 PM, Stanley Shi wrote: > >> As far as I know, there's no combination of hadoop API can do that. >> You can easily get the location of the block (on which DN), but there's >> no way to get the local address of that block file. >> >> >> >> On Thu, Aug 28, 2014 at 11:54 AM, Demai Ni wrote: >> >>> Yehia, >>> >>> No problem at all. I really appreciate your willingness to help. Yeah. >>> now I am able to get such information through two steps, and the first step >>> will be either hadoop fsck or getFileBlockLocations(). and then search >>> the local filesystem, my cluster is using the default from CDH, which is >>> /dfs/dn >>> >>> I would like to it programmatically, so wondering whether someone >>> already done it? or maybe better a hadoop API call already implemented for >>> this exact purpose >>> >>> Demai >>> >>> >>> On Wed, Aug 27, 2014 at 7:58 PM, Yehia Elshater >>> wrote: >>> Hi Demai, Sorry, I missed that you are already tried this out. I think you can construct the block location on the local file system if you have the block pool id and the block id. If you are using cloudera distribution, the default location is under /dfs/dn ( the value of dfs.data.dir, dfs.datanode.data.dir configuration keys). Thanks Yehia On 27 August 2014 21:20, Yehia Elshater wrote: > Hi Demai, > > You can use fsck utility like the following: > > hadoop fsck /path/to/your/hdfs/file -files -blocks -locations -racks > > This will display all the information you need about the blocks of > your file. > > Hope it helps. > Yehia > > > On 27 August 2014 20:18, Demai Ni wrote: > >> Hi, Stanley, >> >> Many thanks. Your method works. For now, I can have two steps >> approach: >> 1) getFileBlockLocations to grab hdfs BlockLocation[] >> 2) use local file system call(like find command) to match the block >> to files on local file system . >> >> Maybe there is an existing Hadoop API to return such info in already? >> >> Demai on the run >> >> On Aug 26, 2014, at 9:14 PM, Stanley Shi wrote: >> >> I am not sure this is what you want but you can try this shell >> command: >> >> find [DATANODE_DIR] -name [blockname] >> >> >> On Tue, Aug 26, 2014 at 6:42 AM, Demai Ni wrote: >> >>> Hi, folks, >>> >>> New in this area. Hopefully to get a couple pointers. >>> >>> I am using Centos and have Hadoop set up using cdh5.1(Hadoop 2.3) >>> >>> I am wondering whether there is a interface to get each hdfs block >>> information in the term of local file system. >>> >>> For example, I can use "Hadoop fsck /tmp/test.txt -files -blocks >>> -racks" to get blockID and its replica on the nodes, such as: repl =3[ >>> /rack/hdfs01, /rack/hdfs02...] >>> >>> With such info, is there a way to >>> 1) login to hfds01, and read the block directly at local file system >>> level? >>> >>> >>> Thanks >>> >>> Demai on the run >> >> >> >> >> -- >> Regards, >> *Stanley Shi,* >> >> > >>> >> >> >> -- >> Regards, >> *Stanley Shi,* >> >> > -- Regards, *Stanley Shi,*
Re: Local file system to access hdfs blocks
Stanley, Thanks. Btw, I found this jira hdfs-2246, which probably match what I am looking for. Demai on the run On Aug 28, 2014, at 11:34 PM, Stanley Shi wrote: > BP-13-7914115-10.122.195.197-14909166276345 is the blockpool information > blk_1073742025 is the block name; > > these names are "private" to teh HDFS system and user should not use them, > right? > But if you really want ot know this, you can check the fsck code to see > whether they are available; > > > On Fri, Aug 29, 2014 at 8:13 AM, Demai Ni wrote: >> Stanley and all, >> >> thanks. I will write a client application to explore this path. A quick >> question again. >> Using the fsck command, I can retrieve all the necessary info >> $ hadoop fsck /tmp/list2.txt -files -blocks -racks >> . >> BP-13-7914115-10.122.195.197-14909166276345:blk_1073742025 len=8 repl=2 >> [/default/10.122.195.198:50010, /default/10.122.195.196:50010] >> >> However, using getFileBlockLocations(), I can't get the block name/id info, >> such as BP-13-7914115-10.122.195.197-14909166276345:blk_1073742025 >> seem the BlockLocation don't provide the public info here. >> http://hadoop.apache.org/docs/current/api/org/apache/hadoop/fs/BlockLocation.html >> >> is there another entry point? somethinig fsck is using? thanks >> >> Demai >> >> >> >> >> On Wed, Aug 27, 2014 at 11:09 PM, Stanley Shi wrote: >>> As far as I know, there's no combination of hadoop API can do that. >>> You can easily get the location of the block (on which DN), but there's no >>> way to get the local address of that block file. >>> >>> >>> >>> On Thu, Aug 28, 2014 at 11:54 AM, Demai Ni wrote: Yehia, No problem at all. I really appreciate your willingness to help. Yeah. now I am able to get such information through two steps, and the first step will be either hadoop fsck or getFileBlockLocations(). and then search the local filesystem, my cluster is using the default from CDH, which is /dfs/dn I would like to it programmatically, so wondering whether someone already done it? or maybe better a hadoop API call already implemented for this exact purpose Demai On Wed, Aug 27, 2014 at 7:58 PM, Yehia Elshater wrote: > Hi Demai, > > Sorry, I missed that you are already tried this out. I think you can > construct the block location on the local file system if you have the > block pool id and the block id. If you are using cloudera distribution, > the default location is under /dfs/dn ( the value of dfs.data.dir, > dfs.datanode.data.dir configuration keys). > > Thanks > Yehia > > > On 27 August 2014 21:20, Yehia Elshater wrote: >> Hi Demai, >> >> You can use fsck utility like the following: >> >> hadoop fsck /path/to/your/hdfs/file -files -blocks -locations -racks >> >> This will display all the information you need about the blocks of your >> file. >> >> Hope it helps. >> Yehia >> >> >> On 27 August 2014 20:18, Demai Ni wrote: >>> Hi, Stanley, >>> >>> Many thanks. Your method works. For now, I can have two steps approach: >>> 1) getFileBlockLocations to grab hdfs BlockLocation[] >>> 2) use local file system call(like find command) to match the block to >>> files on local file system . >>> >>> Maybe there is an existing Hadoop API to return such info in already? >>> >>> Demai on the run >>> >>> On Aug 26, 2014, at 9:14 PM, Stanley Shi wrote: >>> I am not sure this is what you want but you can try this shell command: find [DATANODE_DIR] -name [blockname] On Tue, Aug 26, 2014 at 6:42 AM, Demai Ni wrote: > Hi, folks, > > New in this area. Hopefully to get a couple pointers. > > I am using Centos and have Hadoop set up using cdh5.1(Hadoop 2.3) > > I am wondering whether there is a interface to get each hdfs block > information in the term of local file system. > > For example, I can use "Hadoop fsck /tmp/test.txt -files -blocks > -racks" to get blockID and its replica on the nodes, such as: repl > =3[ /rack/hdfs01, /rack/hdfs02...] > > With such info, is there a way to > 1) login to hfds01, and read the block directly at local file system > level? > > > Thanks > > Demai on the run -- Regards, Stanley Shi, >>> >>> >>> >>> -- >>> Regards, >>> Stanley Shi, >>> > > > > -- > Regards, > Stanley Shi, >
