Will modification of one replica change other two replicas as well?
Hadoop have 3 replication factor, right ?
If I modify one replica, will the other two replicas also change or not ?
hadoop
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Hadoop have 3 replication factor, right ?
If I modify one replica, will the other two replicas also change or not ?
hadoop
add a comment |
Hadoop have 3 replication factor, right ?
If I modify one replica, will the other two replicas also change or not ?
hadoop
Hadoop have 3 replication factor, right ?
If I modify one replica, will the other two replicas also change or not ?
hadoop
hadoop
edited Nov 15 at 22:42
cricket_007
79.1k1142109
79.1k1142109
asked Nov 15 at 12:03
Syed Furquan Ali
11
11
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2 Answers
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But you can't modify the contents of file on hadoop because it is 'write once read many'.So,you first modify it locally and then replicate it on hdfs.So,then the contents of 3 replication are same.
In other words, you "overwrite" the file on HDFS with the local edits
– cricket_007
Nov 15 at 22:43
is there any way to overcome "overwrite" the file on HDFS@cricket_007
.
– code_cody97
Nov 16 at 10:09
add a comment |
By default, HDFS uses a replication factor equal to 3 but it can be changed. HDFS does not allow to alter just one copy of your data block, because block replication should be transparent for the user.
Technically, you can alter one copy by accessing the local file system of a single datanode, and alter the files under the dfs.datanode.data.dir
local direcory, but HDFS is not aware of this change, therfore it will not be replicated for the other copies.
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
But you can't modify the contents of file on hadoop because it is 'write once read many'.So,you first modify it locally and then replicate it on hdfs.So,then the contents of 3 replication are same.
In other words, you "overwrite" the file on HDFS with the local edits
– cricket_007
Nov 15 at 22:43
is there any way to overcome "overwrite" the file on HDFS@cricket_007
.
– code_cody97
Nov 16 at 10:09
add a comment |
But you can't modify the contents of file on hadoop because it is 'write once read many'.So,you first modify it locally and then replicate it on hdfs.So,then the contents of 3 replication are same.
In other words, you "overwrite" the file on HDFS with the local edits
– cricket_007
Nov 15 at 22:43
is there any way to overcome "overwrite" the file on HDFS@cricket_007
.
– code_cody97
Nov 16 at 10:09
add a comment |
But you can't modify the contents of file on hadoop because it is 'write once read many'.So,you first modify it locally and then replicate it on hdfs.So,then the contents of 3 replication are same.
But you can't modify the contents of file on hadoop because it is 'write once read many'.So,you first modify it locally and then replicate it on hdfs.So,then the contents of 3 replication are same.
answered Nov 15 at 14:50
code_cody97
709
709
In other words, you "overwrite" the file on HDFS with the local edits
– cricket_007
Nov 15 at 22:43
is there any way to overcome "overwrite" the file on HDFS@cricket_007
.
– code_cody97
Nov 16 at 10:09
add a comment |
In other words, you "overwrite" the file on HDFS with the local edits
– cricket_007
Nov 15 at 22:43
is there any way to overcome "overwrite" the file on HDFS@cricket_007
.
– code_cody97
Nov 16 at 10:09
In other words, you "overwrite" the file on HDFS with the local edits
– cricket_007
Nov 15 at 22:43
In other words, you "overwrite" the file on HDFS with the local edits
– cricket_007
Nov 15 at 22:43
is there any way to overcome "overwrite" the file on HDFS
@cricket_007
.– code_cody97
Nov 16 at 10:09
is there any way to overcome "overwrite" the file on HDFS
@cricket_007
.– code_cody97
Nov 16 at 10:09
add a comment |
By default, HDFS uses a replication factor equal to 3 but it can be changed. HDFS does not allow to alter just one copy of your data block, because block replication should be transparent for the user.
Technically, you can alter one copy by accessing the local file system of a single datanode, and alter the files under the dfs.datanode.data.dir
local direcory, but HDFS is not aware of this change, therfore it will not be replicated for the other copies.
add a comment |
By default, HDFS uses a replication factor equal to 3 but it can be changed. HDFS does not allow to alter just one copy of your data block, because block replication should be transparent for the user.
Technically, you can alter one copy by accessing the local file system of a single datanode, and alter the files under the dfs.datanode.data.dir
local direcory, but HDFS is not aware of this change, therfore it will not be replicated for the other copies.
add a comment |
By default, HDFS uses a replication factor equal to 3 but it can be changed. HDFS does not allow to alter just one copy of your data block, because block replication should be transparent for the user.
Technically, you can alter one copy by accessing the local file system of a single datanode, and alter the files under the dfs.datanode.data.dir
local direcory, but HDFS is not aware of this change, therfore it will not be replicated for the other copies.
By default, HDFS uses a replication factor equal to 3 but it can be changed. HDFS does not allow to alter just one copy of your data block, because block replication should be transparent for the user.
Technically, you can alter one copy by accessing the local file system of a single datanode, and alter the files under the dfs.datanode.data.dir
local direcory, but HDFS is not aware of this change, therfore it will not be replicated for the other copies.
answered Nov 15 at 16:09
54l3d
3,08721437
3,08721437
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