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Mysql Fabric hash sharding not balanced in shards
Date: August 23, 2016 11:02AM

MySQL Fabric 1.5.6
MySQL version: 5.6.31
O/S version: Centos 6.8

group_id description failure_detector master_uuid
-------- ----------- ---------------- ------------------------------------
global None 1 103383e3-542d-11e6-b7c0-066c5b481b6b
s1 None 1 605fe051-5389-11e6-b394-06fbcce39c6f
s3 None 1 b3689258-5389-11e6-b396-06a644a10425
s2 None 1 ff024a40-5386-11e6-b385-0661de27c503

mapping_id type_name table_name global_group column_name
---------- --------- -------------- ------------ -----------
1 HASH silo_db.Member global id

I'm using python mysql connector to load the data.


When I load the data it don't balance over 3 shards. It's skewing one shard a lot.

Issue is when I query fabric to locate the record, it does say that it's on different shard but it's not loading on the shard. In other words, connector is not loading in the right shard as per fabric. When I ask fabric to locate the record it's not there on that shard. See below

mysqlfabric sharding lookup_servers silo_db.MemberMME 2000
Fabric UUID: 5ca1ab1e-a007-feed-f00d-cab3fe13249e
Time-To-Live: 1

server_uuid address status mode weight
------------------------------------ ----------- ------- ---------- ------
ff024a40-5386-11e6-b385-0661de27c503 s2-mme:3306 PRIMARY READ_WRITE 1.0

This record is not on that shard. It's on shard s1-mme. This is skewing data a lot and totally imbalanced over the shards.

Any help would be highly appreciate that why hash is not working or it's a connector issue while loading.


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Mysql Fabric hash sharding not balanced in shards
August 23, 2016 11:02AM

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