phoenix-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Michael McAllister <mmcallis...@homeaway.com>
Subject Re: Number of regions in SYSTEM.SEQUENCE
Date Tue, 22 Sep 2015 18:47:36 GMT
Mujtaba

Thanks for this information. Seeing as I am using Phoenix 4.2, what is the safe and approved
sequence of steps to drop this table and recreate it as you mention? Additionally, how do
we ensure we don’t lose sequence data?

Michael McAllister
Staff Data Warehouse Engineer | Decision Systems
mmcallister@HomeAway.com<mailto:mmcallister@HomeAway.com> | C: 512.423.7447 | skype:
michael.mcallister.ha<mailto:zimmkate@hotmail.com> | webex: https://h.a/mikewebex

[cid:image002.png@01D080DC.77AD4930]
This electronic communication (including any attachment) is confidential.  If you are not
an intended recipient of this communication, please be advised that any disclosure, dissemination,
distribution, copying or other use of this communication or any attachment is strictly prohibited.
 If you have received this communication in error, please notify the sender immediately by
reply e-mail and promptly destroy all electronic and printed copies of this communication
and any attachment.

On Sep 22, 2015, at 1:32 PM, Mujtaba Chohan <mujtaba@apache.org<mailto:mujtaba@apache.org>>
wrote:

Since Phoenix 4.5.x default has been changed for phoenix.sequence.saltBuckets to not split
sequence table. See this<https://git-wip-us.apache.org/repos/asf?p=phoenix.git;a=blobdiff;f=phoenix-core/src/main/java/org/apache/phoenix/query/QueryServicesOptions.java;h=79776e7f688fc700275d0502e31646afe2bbcb1e;hp=4e8879b1b7a6358db2c1f9ccb4fa169394fec721;hb=18e52cc4ce2384bdc7a9c72d63901058e40f04ae;hpb=b82c5cbccdf4eb944238e69a514841be361bfb6d>
commit. For older versions you can drop sequence table and reconnect with setting client side
phoenix.sequence.saltBuckets property.

On Tue, Sep 22, 2015 at 11:14 AM, Michael McAllister <mmcallister@homeaway.com<mailto:mmcallister@homeaway.com>>
wrote:
Hi

By default SYSTEM.SEQUENCE is installed with 256 regions. In an environment where you don’t
have a large number of tables and regions (yet), the end result of this seems to be that with
hbase balance_switch=true, you end up with a lot of region servers with nothing but empty
SYSTEM.SEQUENCE regions on them. That mans inefficient use of our cluster.

Have there been any best practices developed as to how to deal with this situation?

Michael McAllister
Staff Data Warehouse Engineer | Decision Systems
mmcallister@HomeAway.com<mailto:mmcallister@HomeAway.com> | C: 512.423.7447<tel:512.423.7447>
| skype: michael.mcallister.ha<mailto:zimmkate@hotmail.com> | webex: https://h.a/mikewebex

<image002.png>
This electronic communication (including any attachment) is confidential.  If you are not
an intended recipient of this communication, please be advised that any disclosure, dissemination,
distribution, copying or other use of this communication or any attachment is strictly prohibited.
 If you have received this communication in error, please notify the sender immediately by
reply e-mail and promptly destroy all electronic and printed copies of this communication
and any attachment.



Mime
View raw message