FAQ
This problem is about how to change the replication factor for HBase. This
seems to be a well known problem which can be easily solved by deploying
the configuration settings to the client. But that doesn't work for me.


Here is what I found how our cluster (CDH 4.3) behaved and the work around
I figured out for this.



The standard way how to change the replication factor for HBase with
Cloudera Manager is to go into services -> HDFS -> configuration and change
the dfs.replication setting to the desired value. After that you have to go
to the HBase service (in Cloudera Manager) and click on deploy
configuration. What I found out is that the 'HBase Master' is the 'HDFS
client' who is responsible for the replication setting of HBase. I
therefore checked the correct replication of the client settings (after
clicking on the deploy button in Cloudera Manager) in the following
directory(ies) of the machine where the HBase master is configured (my
hbase cluster has the name hbase1)


fgrep -A 1 repl /etc/hbase/conf.cloudera.hbase1/hdfs-site.xml
     <name>dfs.replication</name>

     <value>2</value>

which shows the correct value after I deployed the client settings in
Cloudera Manager.



After that I restarted the HBase Cluster with Cloudera Manager. The
cloudera-scm-agent then created new directories for the HBase processes (on
each machine where HBase roles are configured). I tried to look up in the
newly created directory for the master to find the new replication setting:


find /var/run/cloudera-scm-agent/process/ -name "hdfs-site.xml" |grep
MASTER| xargs grep -A 1 repl



and didn't get any hits. Creating a new table now with HBase also showed
that the default replication (3) was still active.

My next experiment then was to start the master manually. I first stopped
all master processes (I normaly start multiple masters for redundancy in
failure cases but for this experiment I only started one). I then picked
one of the machines where the master role is configured. I went in the
newly created directory for the master from the last trial (in my case it
was called 1290-hbase-MASTER):


cd /var/run/cloudera-scm-agent/process/1290-hbase-MASTER


There I edited the hdfs-site.xml file and insert the lines:



   <property>

     <name>dfs.replication</name>

     <value>2</value>

   </property>



then I started the master process manually like so:


nohup /usr/lib/hbase/bin/hbase --config
/var/run/cloudera-scm-agent/process/1290-hbase-MASTER master start&



After this I restarted the HBase region servers, and retried to create a
new table. This resulted in a new table that had the desired replication
factor.



To me it seems that there is a bug. In my opinion after deploying the
client configuration and after restart of HDFS and HBase the hdfs-site.xml
file in the masters process directory should contain the entry for
dfs.replication which isn't the case for our cluster (Cloudera 4.3).



Can anybody tell me if I made something wrong or if this is just a bug?



Thanks

Karl-Heinz

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  • Vinithra Varadharajan at Jun 7, 2013 at 6:04 pm
    Hi,
    First off, thanks for the excellent and detailed report!

    I tried reproducing what you're seeing on CM4.5 and CM4.6, but in both
    cases it worked when I did the following:
    1) Go to HDFS service -> Configurations tab -> search for replication
    factor -> change from 3 to 2.
    2) Go to HBase service -> click on Master role -> Restart.
    3) Master role -> Processes tab -> Locate program "hbase/hbase.sh
    ["master","start"]" -> Expand on "Show Configuration Files/Environment" ->
    Inspect hdfs-site.xml
    4) If you want to verify this on the machine, click on the stdout.log which
    is to the left of the configuration files, see which config directory is
    being used on the machine. I've attached an image to show what I'm talking
    about.

    Can you try this again? It's curious why you saw what you saw.

    -Vinithra

    On Fri, Jun 7, 2013 at 8:08 AM, Karl-Heinz Krachenfels wrote:

    This problem is about how to change the replication factor for HBase. This
    seems to be a well known problem which can be easily solved by deploying
    the configuration settings to the client. But that doesn't work for me.


    Here is what I found how our cluster (CDH 4.3) behaved and the work around
    I figured out for this.



    The standard way how to change the replication factor for HBase with
    Cloudera Manager is to go into services -> HDFS -> configuration and change
    the dfs.replication setting to the desired value. After that you have to go
    to the HBase service (in Cloudera Manager) and click on deploy
    configuration. What I found out is that the 'HBase Master' is the 'HDFS
    client' who is responsible for the replication setting of HBase. I
    therefore checked the correct replication of the client settings (after
    clicking on the deploy button in Cloudera Manager) in the following
    directory(ies) of the machine where the HBase master is configured (my
    hbase cluster has the name hbase1)


    fgrep -A 1 repl /etc/hbase/conf.cloudera.hbase1/hdfs-site.xml
    <name>dfs.replication</name>

    <value>2</value>

    which shows the correct value after I deployed the client settings in
    Cloudera Manager.



    After that I restarted the HBase Cluster with Cloudera Manager. The
    cloudera-scm-agent then created new directories for the HBase processes (on
    each machine where HBase roles are configured). I tried to look up in the
    newly created directory for the master to find the new replication setting:


    find /var/run/cloudera-scm-agent/process/ -name "hdfs-site.xml" |grep
    MASTER| xargs grep -A 1 repl



    and didn't get any hits. Creating a new table now with HBase also showed
    that the default replication (3) was still active.

    My next experiment then was to start the master manually. I first stopped
    all master processes (I normaly start multiple masters for redundancy in
    failure cases but for this experiment I only started one). I then picked
    one of the machines where the master role is configured. I went in the
    newly created directory for the master from the last trial (in my case
    it was called 1290-hbase-MASTER):


    cd /var/run/cloudera-scm-agent/process/1290-hbase-MASTER


    There I edited the hdfs-site.xml file and insert the lines:



    <property>

    <name>dfs.replication</name>

    <value>2</value>

    </property>



    then I started the master process manually like so:


    nohup /usr/lib/hbase/bin/hbase --config
    /var/run/cloudera-scm-agent/process/1290-hbase-MASTER master start&



    After this I restarted the HBase region servers, and retried to create a
    new table. This resulted in a new table that had the desired replication
    factor.



    To me it seems that there is a bug. In my opinion after deploying the
    client configuration and after restart of HDFS and HBase the hdfs-site.xml
    file in the masters process directory should contain the entry for
    dfs.replication which isn't the case for our cluster (Cloudera 4.3).



    Can anybody tell me if I made something wrong or if this is just a bug?



    Thanks

    Karl-Heinz


  • Karl-Heinz Krachenfels at Jun 10, 2013 at 9:07 am
    Hi,

    thanks for your help.

    I followed the steps you described and had the same effect.
    'dfs.replication' doesn't find its way into the hdfs-site.xml file.
    Could this be a bug that is fixed in the newer versions of Cloudera Manager?

    Thanks a lot
    Karl-Heinz


    Am Freitag, 7. Juni 2013 20:04:00 UTC+2 schrieb Vinithra:
    Hi,
    First off, thanks for the excellent and detailed report!

    I tried reproducing what you're seeing on CM4.5 and CM4.6, but in both
    cases it worked when I did the following:
    1) Go to HDFS service -> Configurations tab -> search for replication
    factor -> change from 3 to 2.
    2) Go to HBase service -> click on Master role -> Restart.
    3) Master role -> Processes tab -> Locate program "hbase/hbase.sh
    ["master","start"]" -> Expand on "Show Configuration Files/Environment"
    -> Inspect hdfs-site.xml
    4) If you want to verify this on the machine, click on the stdout.log
    which is to the left of the configuration files, see which config directory
    is being used on the machine. I've attached an image to show what I'm
    talking about.

    Can you try this again? It's curious why you saw what you saw.

    -Vinithra


    On Fri, Jun 7, 2013 at 8:08 AM, Karl-Heinz Krachenfels <
    karlh.kr...@gmail.com <javascript:>> wrote:
    This problem is about how to change the replication factor for HBase.
    This seems to be a well known problem which can be easily solved by
    deploying the configuration settings to the client. But that doesn't work
    for me.


    Here is what I found how our cluster (CDH 4.3) behaved and the work
    around I figured out for this.



    The standard way how to change the replication factor for HBase with
    Cloudera Manager is to go into services -> HDFS -> configuration and change
    the dfs.replication setting to the desired value. After that you have to go
    to the HBase service (in Cloudera Manager) and click on deploy
    configuration. What I found out is that the 'HBase Master' is the 'HDFS
    client' who is responsible for the replication setting of HBase. I
    therefore checked the correct replication of the client settings (after
    clicking on the deploy button in Cloudera Manager) in the following
    directory(ies) of the machine where the HBase master is configured (my
    hbase cluster has the name hbase1)


    fgrep -A 1 repl /etc/hbase/conf.cloudera.hbase1/hdfs-site.xml
    <name>dfs.replication</name>

    <value>2</value>

    which shows the correct value after I deployed the client settings in
    Cloudera Manager.



    After that I restarted the HBase Cluster with Cloudera Manager. The
    cloudera-scm-agent then created new directories for the HBase processes (on
    each machine where HBase roles are configured). I tried to look up in the
    newly created directory for the master to find the new replication setting:


    find /var/run/cloudera-scm-agent/process/ -name "hdfs-site.xml" |grep
    MASTER| xargs grep -A 1 repl



    and didn't get any hits. Creating a new table now with HBase also showed
    that the default replication (3) was still active.

    My next experiment then was to start the master manually. I first stopped
    all master processes (I normaly start multiple masters for redundancy in
    failure cases but for this experiment I only started one). I then picked
    one of the machines where the master role is configured. I went in the
    newly created directory for the master from the last trial (in my case
    it was called 1290-hbase-MASTER):


    cd /var/run/cloudera-scm-agent/process/1290-hbase-MASTER


    There I edited the hdfs-site.xml file and insert the lines:



    <property>

    <name>dfs.replication</name>

    <value>2</value>

    </property>



    then I started the master process manually like so:


    nohup /usr/lib/hbase/bin/hbase --config
    /var/run/cloudera-scm-agent/process/1290-hbase-MASTER master start&



    After this I restarted the HBase region servers, and retried to create a
    new table. This resulted in a new table that had the desired replication
    factor.



    To me it seems that there is a bug. In my opinion after deploying the
    client configuration and after restart of HDFS and HBase the hdfs-site.xml
    file in the masters process directory should contain the entry for
    dfs.replication which isn't the case for our cluster (Cloudera 4.3).



    Can anybody tell me if I made something wrong or if this is just a bug?



    Thanks

    Karl-Heinz


  • Darren Lo at Jun 10, 2013 at 3:15 pm
    Hi Karl-Heinz,

    What version of Cloudera Manager are you using? We checked a couple
    different versions already and didn't find this bug. Note that the Cloudera
    Manager version is distinct from the version of CDH you have installed on
    your hosts. You can find the CM version in Support -> About in the upper
    right corner after logging in.

    Thanks,
    Darren

    On Mon, Jun 10, 2013 at 2:07 AM, Karl-Heinz Krachenfels wrote:

    Hi,

    thanks for your help.

    I followed the steps you described and had the same effect.
    'dfs.replication' doesn't find its way into the hdfs-site.xml file.
    Could this be a bug that is fixed in the newer versions of Cloudera
    Manager?

    Thanks a lot
    Karl-Heinz


    Am Freitag, 7. Juni 2013 20:04:00 UTC+2 schrieb Vinithra:
    Hi,
    First off, thanks for the excellent and detailed report!

    I tried reproducing what you're seeing on CM4.5 and CM4.6, but in both
    cases it worked when I did the following:
    1) Go to HDFS service -> Configurations tab -> search for replication
    factor -> change from 3 to 2.
    2) Go to HBase service -> click on Master role -> Restart.
    3) Master role -> Processes tab -> Locate program "hbase/hbase.sh
    ["master","start"]" -> Expand on "Show Configuration Files/Environment"
    -> Inspect hdfs-site.xml
    4) If you want to verify this on the machine, click on the stdout.log
    which is to the left of the configuration files, see which config directory
    is being used on the machine. I've attached an image to show what I'm
    talking about.

    Can you try this again? It's curious why you saw what you saw.

    -Vinithra


    On Fri, Jun 7, 2013 at 8:08 AM, Karl-Heinz Krachenfels <
    karlh.kr...@gmail.com> wrote:
    This problem is about how to change the replication factor for HBase.
    This seems to be a well known problem which can be easily solved by
    deploying the configuration settings to the client. But that doesn't work
    for me.


    Here is what I found how our cluster (CDH 4.3) behaved and the work
    around I figured out for this.



    The standard way how to change the replication factor for HBase with
    Cloudera Manager is to go into services -> HDFS -> configuration and change
    the dfs.replication setting to the desired value. After that you have to go
    to the HBase service (in Cloudera Manager) and click on deploy
    configuration. What I found out is that the 'HBase Master' is the
    'HDFS client' who is responsible for the replication setting of HBase. I
    therefore checked the correct replication of the client settings (after
    clicking on the deploy button in Cloudera Manager) in the following
    directory(ies) of the machine where the HBase master is configured
    (my hbase cluster has the name hbase1)


    fgrep -A 1 repl /etc/hbase/conf.cloudera.**hbase1/hdfs-site.xml
    <name>dfs.replication</name>

    <value>2</value>

    which shows the correct value after I deployed the client settings in
    Cloudera Manager.



    After that I restarted the HBase Cluster with Cloudera Manager. The
    cloudera-scm-agent then created new directories for the HBase processes (on
    each machine where HBase roles are configured). I tried to look up in the
    newly created directory for the master to find the new replication setting:


    find /var/run/cloudera-scm-agent/**process/ -name "hdfs-site.xml"
    grep MASTER| xargs grep -A 1 repl


    and didn't get any hits. Creating a new table now with HBase also showed
    that the default replication (3) was still active.

    My next experiment then was to start the master manually. I first
    stopped all master processes (I normaly start multiple masters for
    redundancy in failure cases but for this experiment I only started one). I
    then picked one of the machines where the master role is configured. I went
    in the newly created directory for the master from the last trial (in
    my case it was called 1290-hbase-MASTER):


    cd /var/run/cloudera-scm-agent/**process/1290-hbase-MASTER


    There I edited the hdfs-site.xml file and insert the lines:



    <property>

    <name>dfs.replication</name>

    <value>2</value>

    </property>



    then I started the master process manually like so:


    nohup /usr/lib/hbase/bin/hbase --config /var/run/cloudera-scm-agent/**process/1290-hbase-MASTER
    master start&



    After this I restarted the HBase region servers, and retried to create a
    new table. This resulted in a new table that had the desired replication
    factor.



    To me it seems that there is a bug. In my opinion after deploying the
    client configuration and after restart of HDFS and HBase the hdfs-site.xml
    file in the masters process directory should contain the entry for
    dfs.replication which isn't the case for our cluster (Cloudera 4.3).



    Can anybody tell me if I made something wrong or if this is just a bug?



    Thanks

    Karl-Heinz



    --
    Thanks,
    Darren
  • Karl-Heinz Krachenfels at Jun 10, 2013 at 4:37 pm
    Hi Darren,

    we use Cloudera Manager 4.1.

    Karl-Heinz


    Am Montag, 10. Juni 2013 17:15:07 UTC+2 schrieb Darren Lo:
    Hi Karl-Heinz,

    What version of Cloudera Manager are you using? We checked a couple
    different versions already and didn't find this bug. Note that the Cloudera
    Manager version is distinct from the version of CDH you have installed on
    your hosts. You can find the CM version in Support -> About in the upper
    right corner after logging in.

    Thanks,
    Darren


    On Mon, Jun 10, 2013 at 2:07 AM, Karl-Heinz Krachenfels <
    karlh.kr...@gmail.com <javascript:>> wrote:
    Hi,

    thanks for your help.

    I followed the steps you described and had the same effect.
    'dfs.replication' doesn't find its way into the hdfs-site.xml file.
    Could this be a bug that is fixed in the newer versions of Cloudera
    Manager?

    Thanks a lot
    Karl-Heinz


    Am Freitag, 7. Juni 2013 20:04:00 UTC+2 schrieb Vinithra:
    Hi,
    First off, thanks for the excellent and detailed report!

    I tried reproducing what you're seeing on CM4.5 and CM4.6, but in both
    cases it worked when I did the following:
    1) Go to HDFS service -> Configurations tab -> search for replication
    factor -> change from 3 to 2.
    2) Go to HBase service -> click on Master role -> Restart.
    3) Master role -> Processes tab -> Locate program "hbase/hbase.sh
    ["master","start"]" -> Expand on "Show Configuration Files/Environment"
    -> Inspect hdfs-site.xml
    4) If you want to verify this on the machine, click on the stdout.log
    which is to the left of the configuration files, see which config directory
    is being used on the machine. I've attached an image to show what I'm
    talking about.

    Can you try this again? It's curious why you saw what you saw.

    -Vinithra


    On Fri, Jun 7, 2013 at 8:08 AM, Karl-Heinz Krachenfels <
    karlh.kr...@gmail.com> wrote:
    This problem is about how to change the replication factor for HBase.
    This seems to be a well known problem which can be easily solved by
    deploying the configuration settings to the client. But that doesn't work
    for me.


    Here is what I found how our cluster (CDH 4.3) behaved and the work
    around I figured out for this.



    The standard way how to change the replication factor for HBase with
    Cloudera Manager is to go into services -> HDFS -> configuration and change
    the dfs.replication setting to the desired value. After that you have to go
    to the HBase service (in Cloudera Manager) and click on deploy
    configuration. What I found out is that the 'HBase Master' is the
    'HDFS client' who is responsible for the replication setting of HBase. I
    therefore checked the correct replication of the client settings (after
    clicking on the deploy button in Cloudera Manager) in the following
    directory(ies) of the machine where the HBase master is configured
    (my hbase cluster has the name hbase1)


    fgrep -A 1 repl /etc/hbase/conf.cloudera.**hbase1/hdfs-site.xml
    <name>dfs.replication</name>

    <value>2</value>

    which shows the correct value after I deployed the client settings in
    Cloudera Manager.



    After that I restarted the HBase Cluster with Cloudera Manager. The
    cloudera-scm-agent then created new directories for the HBase processes (on
    each machine where HBase roles are configured). I tried to look up in the
    newly created directory for the master to find the new replication setting:


    find /var/run/cloudera-scm-agent/**process/ -name "hdfs-site.xml"
    grep MASTER| xargs grep -A 1 repl


    and didn't get any hits. Creating a new table now with HBase also
    showed that the default replication (3) was still active.

    My next experiment then was to start the master manually. I first
    stopped all master processes (I normaly start multiple masters for
    redundancy in failure cases but for this experiment I only started one). I
    then picked one of the machines where the master role is configured. I went
    in the newly created directory for the master from the last trial (in
    my case it was called 1290-hbase-MASTER):


    cd /var/run/cloudera-scm-agent/**process/1290-hbase-MASTER


    There I edited the hdfs-site.xml file and insert the lines:



    <property>

    <name>dfs.replication</name>

    <value>2</value>

    </property>



    then I started the master process manually like so:


    nohup /usr/lib/hbase/bin/hbase --config /var/run/cloudera-scm-agent/*
    *process/1290-hbase-MASTER master start&



    After this I restarted the HBase region servers, and retried to create
    a new table. This resulted in a new table that had the desired replication
    factor.



    To me it seems that there is a bug. In my opinion after deploying the
    client configuration and after restart of HDFS and HBase the hdfs-site.xml
    file in the masters process directory should contain the entry for
    dfs.replication which isn't the case for our cluster (Cloudera 4.3).



    Can anybody tell me if I made something wrong or if this is just a bug?



    Thanks

    Karl-Heinz



    --
    Thanks,
    Darren
  • Darren Lo at Jun 11, 2013 at 3:25 am
    Hi Karl-Heinz,

    It looks like there's a bug in CM4.1 where this is not correctly getting
    propagated to HBase Roles. This is fixed in newer versions of CM (we've
    just released CM4.6). There are many other new features in CM4.6, including
    adding monitoring and charting to the free version (Standard Edition), so I
    highly recommend upgrading when you can.

    Thanks,
    Darren

    On Mon, Jun 10, 2013 at 9:37 AM, Karl-Heinz Krachenfels wrote:

    Hi Darren,

    we use Cloudera Manager 4.1.

    Karl-Heinz


    Am Montag, 10. Juni 2013 17:15:07 UTC+2 schrieb Darren Lo:
    Hi Karl-Heinz,

    What version of Cloudera Manager are you using? We checked a couple
    different versions already and didn't find this bug. Note that the Cloudera
    Manager version is distinct from the version of CDH you have installed on
    your hosts. You can find the CM version in Support -> About in the upper
    right corner after logging in.

    Thanks,
    Darren


    On Mon, Jun 10, 2013 at 2:07 AM, Karl-Heinz Krachenfels <
    karlh.kr...@gmail.com> wrote:
    Hi,

    thanks for your help.

    I followed the steps you described and had the same effect.
    'dfs.replication' doesn't find its way into the hdfs-site.xml file.
    Could this be a bug that is fixed in the newer versions of Cloudera
    Manager?

    Thanks a lot
    Karl-Heinz


    Am Freitag, 7. Juni 2013 20:04:00 UTC+2 schrieb Vinithra:
    Hi,
    First off, thanks for the excellent and detailed report!

    I tried reproducing what you're seeing on CM4.5 and CM4.6, but in both
    cases it worked when I did the following:
    1) Go to HDFS service -> Configurations tab -> search for replication
    factor -> change from 3 to 2.
    2) Go to HBase service -> click on Master role -> Restart.
    3) Master role -> Processes tab -> Locate program "hbase/hbase.sh
    ["master","start"]" -> Expand on "Show Configuration
    Files/Environment" -> Inspect hdfs-site.xml
    4) If you want to verify this on the machine, click on the stdout.log
    which is to the left of the configuration files, see which config directory
    is being used on the machine. I've attached an image to show what I'm
    talking about.

    Can you try this again? It's curious why you saw what you saw.

    -Vinithra


    On Fri, Jun 7, 2013 at 8:08 AM, Karl-Heinz Krachenfels <
    karlh.kr...@gmail.com> wrote:
    This problem is about how to change the replication factor for HBase.
    This seems to be a well known problem which can be easily solved by
    deploying the configuration settings to the client. But that doesn't work
    for me.


    Here is what I found how our cluster (CDH 4.3) behaved and the work
    around I figured out for this.



    The standard way how to change the replication factor for HBase with
    Cloudera Manager is to go into services -> HDFS -> configuration and change
    the dfs.replication setting to the desired value. After that you have to go
    to the HBase service (in Cloudera Manager) and click on deploy
    configuration. What I found out is that the 'HBase Master' is the
    'HDFS client' who is responsible for the replication setting of HBase. I
    therefore checked the correct replication of the client settings (after
    clicking on the deploy button in Cloudera Manager) in the following
    directory(ies) of the machine where the HBase master is configured
    (my hbase cluster has the name hbase1)


    fgrep -A 1 repl /etc/hbase/conf.cloudera.**hbase**1/hdfs-site.xml
    <name>dfs.replication</name>

    <value>2</value>

    which shows the correct value after I deployed the client settings in
    Cloudera Manager.



    After that I restarted the HBase Cluster with Cloudera Manager. The
    cloudera-scm-agent then created new directories for the HBase processes (on
    each machine where HBase roles are configured). I tried to look up in the
    newly created directory for the master to find the new replication setting:


    find /var/run/cloudera-scm-agent/**pr**ocess/ -name "hdfs-site.xml"
    grep MASTER| xargs grep -A 1 repl


    and didn't get any hits. Creating a new table now with HBase also
    showed that the default replication (3) was still active.

    My next experiment then was to start the master manually. I first
    stopped all master processes (I normaly start multiple masters for
    redundancy in failure cases but for this experiment I only started one). I
    then picked one of the machines where the master role is configured. I went
    in the newly created directory for the master from the last trial (in
    my case it was called 1290-hbase-MASTER):


    cd /var/run/cloudera-scm-agent/**pr**ocess/1290-hbase-MASTER


    There I edited the hdfs-site.xml file and insert the lines:



    <property>

    <name>dfs.replication</name>

    <value>2</value>

    </property>



    then I started the master process manually like so:


    nohup /usr/lib/hbase/bin/hbase --config /var/run/cloudera-scm-agent/
    **pr**ocess/1290-hbase-MASTER master start&



    After this I restarted the HBase region servers, and retried to create
    a new table. This resulted in a new table that had the desired replication
    factor.



    To me it seems that there is a bug. In my opinion after deploying the
    client configuration and after restart of HDFS and HBase the hdfs-site.xml
    file in the masters process directory should contain the entry for
    dfs.replication which isn't the case for our cluster (Cloudera 4.3).



    Can anybody tell me if I made something wrong or if this is just a bug?



    Thanks

    Karl-Heinz



    --
    Thanks,
    Darren

    --
    Thanks,
    Darren

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