Hi Shawn,
OK, got that.
Would shuffling or shifting the replicas bring any benfit or is it just wasted
time?
-------- -------- --------
| ---- | | ---- | | ---- |
shard1 | |r1| | | |r2| | | |r3| |
| ---- | | ---- | | ---- |
| | | | | |
| ---- | | ---- | | ---- |
shard2 | |r3| | | |r1| | | |r2| |
| ---- | | ---- | | ---- |
| | | | | |
| ---- | | ---- | | ---- |
shard3 | |r2| | | |r3| | | |r1| |
| ---- | | ---- | | ---- |
-------- -------- --------
host1 host2 host3
Regards
Bernd
Am 19.04.2018 um 14:43 schrieb Shawn Heisey:
> On 4/19/2018 6:28 AM, Bernd Fehling wrote:
>> How would you setup a SolrCloud an why?
>>
>>
>> shard1 shard2 shard3
>> -------- -------- --------
>> | ---- | | ---- | | ---- |
>> | |r1| | | |r1| | | |r1| |
>> | ---- | | ---- | | ---- |
>> | | | | | |
>> | ---- | | ---- | | ---- |
>> | |r2| | | |r2| | | |r2| |
>> | ---- | | ---- | | ---- |
>> | | | | | |
>> | ---- | | ---- | | ---- |
>> | |r3| | | |r3| | | |r3| |
>> | ---- | | ---- | | ---- |
>> -------- -------- --------
>> host1 host2 host3
>
> I'm assuming that "r1" means replica1.
>
> If you set it up this way, you lose one third of the whole index (all
> replicas of one shard) if *any* host goes down. All queries will fail in
> that situation if shards.tolerant is not set. With shards.tolerant=true, you
> would get partial results.
>
> So you have three machines that are all single points of failure. This setup
> is a bad idea.
>
>> -------- -------- --------
>> | ---- | | ---- | | ---- |
>> shard1 | |r1| | | |r2| | | |r3| |
>> | ---- | | ---- | | ---- |
>> | | | | | |
>> | ---- | | ---- | | ---- |
>> shard2 | |r1| | | |r2| | | |r3| |
>> | ---- | | ---- | | ---- |
>> | | | | | |
>> | ---- | | ---- | | ---- |
>> shard3 | |r1| | | |r2| | | |r3| |
>> | ---- | | ---- | | ---- |
>> -------- -------- --------
>> host1 host2 host3
>
> With this setup, when any host fails, you still have two working replicas of
> all shards. If two hosts fail, you still have one working
> replica. There are no single points of failure, as long as your clients are
> able to direct queries to a working replica. SolrJ clients using
> CloudSolrClient will do this automatically. Other clients may need a load
> balancer sitting in front of the cloud.
>
> This is the recommended way of setting up replicas.
>
> Thanks,
> Shawn
>
