Walter...
Thanks for the additional data points. Clearly we're a long way from
needing anything too complex.
Cheers!
...scott
On 3/14/18 1:12 PM, Walter Underwood wrote:
That would be my recommendation for a first setup. One Solr instance per host,
one shard per collection. We run 5 million document cores with 8 GB of heap for
the JVM. We size the RAM so that all the indexes fit in OS filesystem buffers.
Our big cluster is 32 hosts, 21 million documents in four shards. Each host is
a 36 processor Amazon instance. Each host has one 8 GB Solr process (Solr
6.6.2, java 8u121, G1 collector). No faceting, but we get very long queries,
average length is 25 terms.
wunder
Walter Underwood
wun...@wunderwood.org
http://observer.wunderwood.org/ (my blog)
On Mar 14, 2018, at 12:50 PM, Scott Prentice <s...@leximation.com> wrote:
Erick...
Thanks. Yes. I think we were just going shard-happy without really
understanding the purpose. I think we'll start by keeping things simple .. no
shards, fewer replicas, maybe a bit more RAM. Then we can assess the
performance and make adjustments as needed.
Yes, that's the main reason for moving from our current non-cloud Solr setup to
SolrCloud .. future flexibility as well as greater stability.
Thanks!
...scott
On 3/14/18 11:34 AM, Erick Erickson wrote:
Scott:
Eventually you'll hit the limit of your hardware, regardless of VMs.
I've seen multiple VMs help a lot when you have really beefy hardware,
as in 32 cores, 128G memory and the like. Otherwise it's iffier.
re: sharding or not. As others wrote, sharding is only useful when a
single collection grows past the limits of your hardware. Until that
point, it's usually a better bet to get better hardware than shard.
I've seen 300M docs fit in a single shard. I've also seen 10M strain
pretty beefy hardware.. but from what you've said multiple shards are
really not something you need to worry about.
About balancing all this across VMs and/or machines. You have a _lot_
of room to balance things. Let's say you put all your collections on
one physical machine to start (not recommending, just sayin'). 6
months from now you need to move collections 1-10 to another machine
due to growth. You:
1> spin up a new machine
2> build out collections 1-10 on those machines by using the
Collections API ADDREPLICA.
3> once the new replicas are healthy. DELETEREPLICA on the old hardware.
No down time. No configuration to deal with, SolrCloud will take care
of it for you.
Best,
Erick
On Wed, Mar 14, 2018 at 9:32 AM, Scott Prentice <s...@leximation.com> wrote:
Emir...
Thanks for the input. Our larger collections are localized content, so it
may make sense to shard those so we can target the specific index. I'll need
to confirm how it's being used, if queries are always within a language or
if they are cross-language.
Thanks also for the link .. very helpful!
All the best,
...scott
On 3/14/18 2:21 AM, Emir Arnautović wrote:
Hi Scott,
There is no definite answer - it depends on your documents and query
patterns. Sharding does come with an overhead but also allows Solr to
parallelise search. Query latency is usually something that tells you if you
need to split collection to multiple shards or not. In caseIf you are ok
with latency there is no need to split. Other scenario where shards make
sense is when routing is used in majority of queries so that enables you to
query only subset of documents.
Also, there is indexing aspect where sharding helps - in case of high
indexing throughput is needed, having multiple shards will spread indexing
load to multiple servers.
It seems to me that there is no high indexing throughput requirement and
the main criteria should be query latency.
Here is another blog post talking about this subject:
http://www.od-bits.com/2018/01/solrelasticsearch-capacity-planning.html
<http://www.od-bits.com/2018/01/solrelasticsearch-capacity-planning.html>
Thanks,
Emir
--
Monitoring - Log Management - Alerting - Anomaly Detection
Solr & Elasticsearch Consulting Support Training - http://sematext.com/
On 14 Mar 2018, at 01:01, Scott Prentice <s...@leximation.com> wrote:
We're in the process of moving from 12 single-core collections (non-cloud
Solr) on 3 VMs to a SolrCloud setup. Our collections aren't huge, ranging in
size from 50K to 150K documents with one at 1.2M docs. Our max query
frequency is rather low .. probably no more than 10-20/min. We do update
frequently, maybe 10-100 documents every 10 mins.
Our prototype setup is using 3 VMs (4 core, 16GB RAM each), and we've got
each collection split into 2 shards with 3 replicas (one per VM). Also,
Zookeeper is running on each VM. I understand that it's best to have each ZK
server on a separate machine, but hoping this will work for now.
This all seemed like a good place to start, but after reading lots of
articles and posts, I'm thinking that maybe our smaller collections (under
100K docs) should just be one shard each, and maybe the 1.2M collection
should be more like 6 shards. How do you decide how many shards is right?
Also, our current live system is separated into dev/stage/prod tiers,
not, all of these tiers are together on each of the cloud VMs. This bothers
some people, thinking that it may make our production environment less
stable. I know that in an ideal world, we'd have them all on separate
systems, but with the replication, it seems like we're going to make the
overall system more stable. Is this a correct understanding?
I'm just wondering anyone has opinions on whether we're going in a
reasonable direction or not. Are there any articles that discuss these
initial sizing/scoping issues?
Thanks!
...scott
