Yokozuna inconsistent search results

Oleksiy Krivoshey oleksiyk at gmail.com
Mon Apr 4 10:15:17 EDT 2016


Continuation...

The new index has the same inconsistent search results problem.
I was making a snapshot of `search aae-status` command almost each day.
There were absolutely no Yokozuna errors in logs.

I can see that some AAE trees were not expired (built > 20 days ago). I can
also see that on two nodes (of 5) last AAE exchanges happened > 20 days ago.

For now I have issued ` riak_core_util:rpc_every_member_ann(yz_entropy_mgr,
expire_trees, [], 5000).` on each node again. I will wait 10 days more but
I don't think that will fix anything.


On 25 March 2016 at 09:28, Oleksiy Krivoshey <oleksiyk at gmail.com> wrote:

> One interesting moment happened when I tried removing the index:
>
> - this index was associated with a bucket type, called fs_chunks
> - so I first called RpbSetBucketTypeReq to set search_index: _dont_index_
> - i then tried to remove the index with RpbYokozunaIndexDeleteReq which
> failed with "index is in use" and list of all buckets of the fs_chunks type
> - for some reason all these buckets had their own search_index property
> set to that same index
>
> How can this happen if I definitely never set the search_index property
> per bucket?
>
> On 24 March 2016 at 22:41, Oleksiy Krivoshey <oleksiyk at gmail.com> wrote:
>
>> OK!
>>
>> On 24 March 2016 at 21:11, Magnus Kessler <mkessler at basho.com> wrote:
>>
>>> Hi Oleksiy,
>>>
>>> On 24 March 2016 at 14:55, Oleksiy Krivoshey <oleksiyk at gmail.com> wrote:
>>>
>>>> Hi Magnus,
>>>>
>>>> Thanks! I guess I will go with index deletion because I've already
>>>> tried expiring the trees before.
>>>>
>>>> Do I need to delete AAE data somehow or removing the index is enough?
>>>>
>>>
>>> If you expire the AAE trees with the commands I posted earlier, there
>>> should be no need to remove the AAE data directories manually.
>>>
>>> I hope this works for you. Please monitor the tree rebuild and exchanges
>>> with `riak-admin search aae-status` for the next few days. In particular
>>> the exchanges should be ongoing on a continuous basis once all trees have
>>> been rebuilt. If they don't, please let me know. At that point you should
>>> also gather `riak-debug` output from all nodes before it gets rotated out
>>> after 5 days by default.
>>>
>>> Kind Regards,
>>>
>>> Magnus
>>>
>>>
>>>>
>>>> On 24 March 2016 at 13:28, Magnus Kessler <mkessler at basho.com> wrote:
>>>>
>>>>> Hi Oleksiy,
>>>>>
>>>>> As a first step, I suggest to simply expire the Yokozuna AAE trees
>>>>> again if the output of `riak-admin search aae-status` still suggests that
>>>>> no recent exchanges have taken place. To do this, run `riak attach` on one
>>>>> node and then
>>>>>
>>>>> riak_core_util:rpc_every_member_ann(yz_entropy_mgr, expire_trees, [], 5000).
>>>>>
>>>>>
>>>>> Exit from the riak console with `Ctrl+G q`.
>>>>>
>>>>> Depending on your settings and amount of data the full index should be
>>>>> rebuilt within the next 2.5 days (for a cluster with ring size 128 and
>>>>> default settings). You can monitor the progress with `riak-admin search
>>>>> aae-status` and also in the logs, which should have messages along the
>>>>> lines of
>>>>>
>>>>> 2016-03-24 10:28:25.372 [info]
>>>>> <0.4647.6477>@yz_exchange_fsm:key_exchange:179 Repaired 83055 keys during
>>>>> active anti-entropy exchange of partition
>>>>> 1210306043414653979137426502093171875652569137152 for preflist
>>>>> {1164634117248063262943561351070788031288321245184,3}
>>>>>
>>>>>
>>>>> Re-indexing can put additional strain on the cluster and may cause
>>>>> elevated latency on a cluster already under heavy load. Please monitor the
>>>>> response times while the cluster is re-indexing data.
>>>>>
>>>>> If the cluster load allows it, you can force more rapid re-indexing by
>>>>> changing a few parameters. Again at the `riak attach` console, run
>>>>>
>>>>> riak_core_util:rpc_every_member_ann(application, set_env, [yokozuna, anti_entropy_build_limit, {4, 60000}], 5000).
>>>>> riak_core_util:rpc_every_member_ann(application, set_env, [yokozuna, anti_entropy_concurrency, 5], 5000).
>>>>>
>>>>> This will allow up to 4 trees per node to be built/exchanged per hour,
>>>>> with up to 5 concurrent exchanges throughout the cluster. To return back to
>>>>> the default settings, use
>>>>>
>>>>> riak_core_util:rpc_every_member_ann(application, set_env, [yokozuna, anti_entropy_build_limit, {1, 360000}], 5000).
>>>>> riak_core_util:rpc_every_member_ann(application, set_env, [yokozuna, anti_entropy_concurrency, 2], 5000).
>>>>>
>>>>>
>>>>> If the cluster still doesn't make any progress with automatically
>>>>> re-indexing data, the next steps are pretty much what you already
>>>>> suggested, to drop the existing index and re-index from scratch. I'm
>>>>> assuming that losing the indexes temporarily is acceptable to you at this
>>>>> point.
>>>>>
>>>>> Using any client API that supports RpbYokozunaIndexDeleteReq, you can
>>>>> drop the index from all Solr instances, losing any data stored there
>>>>> immediately. Next, you'll have to re-create the index. I have tried this
>>>>> with the python API, where I deleted the index and re-created it with the
>>>>> same already uploaded schema:
>>>>>
>>>>> from riak import RiakClient
>>>>>
>>>>> c = RiakClient()
>>>>> c.delete_search_index('my_index')
>>>>> c.create_search_index('my_index', 'my_schema')
>>>>>
>>>>> Note that simply deleting the index does not remove it's existing
>>>>> association with any bucket or bucket type. Any PUT operations on these
>>>>> buckets will lead to indexing failures being logged until the index has
>>>>> been recreated. However, this also means that no separate operation in
>>>>> `riak-admin` is required to associate the newly recreated index with the
>>>>> buckets again.
>>>>>
>>>>> After recreating the index expire the trees as explained previously.
>>>>>
>>>>> Let us know if this solves your issue.
>>>>>
>>>>> Kind Regards,
>>>>>
>>>>> Magnus
>>>>>
>>>>>
>>>>> On 24 March 2016 at 08:44, Oleksiy Krivoshey <oleksiyk at gmail.com>
>>>>> wrote:
>>>>>
>>>>>> This is how things are looking after two weeks:
>>>>>>
>>>>>> - there are no solr indexing issues for a long period (2 weeks)
>>>>>> - there are no yokozuna errors at all for 2 weeks
>>>>>> - there is an index with all empty schema, just _yz_* fields, objects
>>>>>> stored in a bucket(s) are binary and so are not analysed by yokozuna
>>>>>> - same yokozuna query repeated gives different number for num_found,
>>>>>> typically the difference between real number of keys in a bucket and
>>>>>> num_found is about 25%
>>>>>> - number of keys repaired by AAE (according to logs) is about 1-2 per
>>>>>> few hours (number of keys "missing" in index is close to 1,000,000)
>>>>>>
>>>>>> Should I now try to delete the index and yokozuna AAE data and wait
>>>>>> another 2 weeks? If yes - how should I delete the index and AAE data?
>>>>>> Will RpbYokozunaIndexDeleteReq be enough?
>>>>>>
>>>>>>
>>>>>>
>>>>> --
>>>>> Magnus Kessler
>>>>> Client Services Engineer
>>>>> Basho Technologies Limited
>>>>>
>>>>> Registered Office - 8 Lincoln’s Inn Fields London WC2A 3BP Reg 07970431
>>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> Magnus Kessler
>>> Client Services Engineer
>>> Basho Technologies Limited
>>>
>>> Registered Office - 8 Lincoln’s Inn Fields London WC2A 3BP Reg 07970431
>>>
>>
>>
>
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