On 7 Feb 2017, at 08:17, my hue <[email protected]> wrote:
> Dear John and Russell Brown,
>
> * How fast is your turnaround time between an update and a fetch?
>
> The turnaround time between an update and a fetch about 1 second.
> During my team and I debug, we adjusted haproxy with the scenario as follow:
>
> Scenario 1 : round robin via 5 nodes of cluster
>
> We meet issue at scenario 1 and we are afraid of that timeout can be occurs
> between nodes,
> make us still get stale data. Then we performed scenario 2
>
> Scenario 2: Disable round robin and only route request to node 1. Cluster
> still is 5 nodes.
> With this case we ensure that request update and fetch always come to and
> from node 1.
> And the issue still occurs.
>
> At the fail time, I hoped that can get any error log from riak nodes to give
> me any information.
> But riak log show to me nothing and everything is ok.
>
> * What operation are you performing?
>
> I used :
>
> riakc_pb_socket:update_type(Pid, {Bucket-Type, Bucket}, Key,
> riakc_map:to_op(Map), []).
> riakc_pb_socket:fetch_type(Pid, {BucketType, Bucket}, Key, []).
What operation are you performing? What is the update you perform? Do you set a
register value, add a register, remove a register?
>
> * It looks like the map is a single level map of last-write-wins registers.
> Is there a chance that the time on the node handling the update is behind the
> value in the lww-register?
>
> => I am not sure about logic show conflict of internal riak node. And the
> issue never happens if I used single node.
> My bucket properties as follow :
>
> {"props":{"name":"menu","active":true,"allow_mult":true,"backend":"bitcask_mult","basic_quorum":false,"big_vclock":50,"chash_keyfun":{"mod":"riak_core_util","fun":"chash_std_keyfun"},"claimant":"[email protected]","datatype":"map","dvv_enabled":true,"dw":"quorum","last_write_wins":false,"linkfun":{"mod":"riak_kv_wm_link_walker","fun":"mapreduce_linkfun"},"n_val":3,"name":"menu","notfound_ok":true,"old_vclock":86400,"postcommit":[],"pr":0,"precommit":[],"pw":0,"r":"quorum","rw":"quorum","search_index":"menu_idx","small_vclock":50,"w":"quorum","young_vclock":20}}
>
> Note :
> + "datatype":"map"
> + "last_write_wins": false
> + "dvv_enabled": true
> + "allow_mult": true
>
>
> * Have you tried using the `modify_type` operation in riakc_pb_socket which
> does the fetch/update operation in sequence for you?
>
> => I dot not use yet, but my action is sequence with fetch and then update.
> Might be I will try modify_type to see.
>
> * Anything in the error logs on any of the nodes?
>
> => From the node log, no errror report at fail time.
>
> * Is the opaque context identical from the fetch and then later after the
> update?
>
> => There is the context got from fetch and that context used with update.
> And during our debug time with string of sequence : fetch , update, fetch ,
> update , .... the context I saw always the same at
> fetch data.
>
> Best regards,
> Hue Tran
>
>
>
> On Tue, Feb 7, 2017 at 2:11 AM, John Daily <[email protected]> wrote:
> Originally I suspected the context which allows Riak to resolve conflicts was
> not present in your data, but I see it in your map structure. Thanks for
> supplying such a detailed description.
>
> How fast is your turnaround time between an update and a fetch? Even if the
> cluster is healthy it’s not impossible to see a timeout between nodes, which
> could result in a stale retrieval. Have you verified whether the stale data
> persists?
>
> A single node cluster gives an advantage that you’ll never see in a real
> cluster: a perfectly synchronized clock. It also reduces (but does not
> completely eliminate) the possibility of an internal timeout between
> processes.
>
> -John
>
>> On Feb 6, 2017, at 1:02 PM, my hue <[email protected]> wrote:
>>
>> Dear Riak Team,
>>
>> I and my team used riak as database for my production with an cluster
>> including 5 nodes.
>> While production run, we meet an critical bug that is sometimes fail to
>> update document.
>> I and my colleagues performed debug and detected an issue with the scenario
>> as follow:
>>
>> + fetch document
>> + change value of document
>> + update document
>>
>> Repeat about 10 times and will meet fail. With the document is updated
>> continually,
>> sometimes will face update fail.
>>
>> The first time, 5 nodes of cluster we used riak version 2.1.1.
>> After meet above bug, we upgraded to use riak version 2.2.0 and this issue
>> still occurs.
>>
>> Via many time test, debug using Tcpdump at riak node :
>>
>> tcpdump -A -ttt -i {interface} src host {host} and dst port {port}
>>
>> And together with the command:
>>
>> riak-admin status | grep "node_puts_map\| node_puts_map_total\|
>> node_puts_total\| vnode_map_update_total\| vnode_puts_total\"
>>
>> we got that the riak server already get the update request.
>> However, do not know why riak backend fail to update document.
>> At the fail time, from riak server log everything is ok.
>>
>> Then we removed cluster and use a single riak server, and see that above
>> bug never happen.
>>
>> For that reason, think that is only happen with cluster work. We took
>> research on basho riak document and our riak configure
>> seems that like suggestion from document. We totally blocked on this issue
>> and hope that can get support from you
>> so that can obtain a stable work from riak database for our production.
>> Thank you so much. Hope that can get your reply soon.
>>
>>
>> * The following is our riak node information :
>>
>> Riak version: 2.2.0
>> OS : CentOS Linux release 7.2.1511
>> Cpu : 4 core
>> Memory : 4G
>> Riak configure : the attached file "riak.conf"
>>
>> Note :
>>
>> - We mostly using default configure of riak configure except that we used
>> storage backend is multi
>>
>> storage_backend = multi
>> multi_backend.bitcask_mult.storage_backend = bitcask
>> multi_backend.bitcask_mult.bitcask.data_root = /var/lib/riak/bitcask_mult
>> multi_backend.default = bitcask_mult
>>
>> -----------------------------------------------------------------------------------------------------------------------------
>>
>> - Bucket type created with the following command:
>>
>> riak-admin bucket-type create dev_restor
>> '{"props":{"backend":"bitcask_mult","datatype":"map"}}'
>> riak-admin bucket-type activate dev_restor
>>
>> -----------------------------------------------------------------------------------------------------------------------------
>>
>> - Bucket Type Status :
>>
>> >> riak-admin bucket-type status dev_restor
>>
>> dev_restor is active
>> young_vclock: 20
>> w: quorum
>> small_vclock: 50
>> rw: quorum
>> r: quorum
>> pw: 0
>> precommit: []
>> pr: 0
>> postcommit: []
>> old_vclock: 86400
>> notfound_ok: true
>> n_val: 3
>> linkfun: {modfun,riak_kv_wm_link_walker,mapreduce_linkfun}
>> last_write_wins: false
>> dw: quorum
>> dvv_enabled: true
>> chash_keyfun: {riak_core_util,chash_std_keyfun}
>> big_vclock: 50
>> basic_quorum: false
>> backend: <<"bitcask_mult">>
>> allow_mult: true
>> datatype: map
>> active: true
>> claimant: '[email protected]'
>>
>> -----------------------------------------------------------------------------------------------------------------------------
>>
>> - Bucket Property :
>>
>> {"props":{"name":"menu","active":true,"allow_mult":true,"backend":"bitcask_mult","basic_quorum":false,"big_vclock":50,"chash_keyfun":{"mod":"riak_core_util","fun":"chash_std_keyfun"},"claimant":"[email protected]","datatype":"map","dvv_enabled":true,"dw":"quorum","last_write_wins":false,"linkfun":{"mod":"riak_kv_wm_link_walker","fun":"mapreduce_linkfun"},"n_val":3,"name":"menu","notfound_ok":true,"old_vclock":86400,"postcommit":[],"pr":0,"precommit":[],"pw":0,"r":"quorum","rw":"quorum","search_index":"menu_idx","small_vclock":50,"w":"quorum","young_vclock":20}}
>>
>>
>> -----------------------------------------------------------------------------------------------------------------------------
>>
>> - Member status :
>>
>> >> riak-admin member-status
>>
>> ================================= Membership
>> ==================================
>> Status Ring Pending Node
>> -------------------------------------------------------------------------------
>> valid 18.8% -- '[email protected]'
>> valid 18.8% -- '[email protected]'
>> valid 18.8% -- '[email protected]'
>> valid 25.0% -- '[email protected]'
>> valid 18.8% -- '[email protected]'
>> -------------------------------------------------------------------------------
>> Valid:5 / Leaving:0 / Exiting:0 / Joining:0 / Down:0
>>
>>
>> -----------------------------------------------------------------------------------------------------------------------------
>>
>> - Ring
>>
>> >> riak-admin status | grep ring
>>
>> ring_creation_size : 64
>> ring_members : ['[email protected]','[email protected]',
>> '[email protected]','[email protected]',
>> '[email protected]']
>> ring_num_partitions : 64
>> ring_ownership : <<"[{'[email protected]',12},\n
>> {'[email protected]',12},\n {'[email protected]',12},\n
>> {'[email protected]',12},\n {'[email protected]',16}]">>
>> rings_reconciled : 0
>> rings_reconciled_total : 31
>>
>> -----------------------------------------------------------------------------------------------------------------------------
>>
>> * The riak client :
>>
>> + riak-erlang-client: https://github.com/basho/riak-erlang-client
>> + release : 2.4.2
>>
>> -----------------------------------------------------------------------------------------------------------------------------
>>
>> * Riak client API used:
>>
>> + Insert/Update:
>>
>> riakc_pb_socket:update_type(Pid, {Bucket-Type, Bucket}, Key,
>> riakc_map:to_op(Map), []).
>>
>> + Fetch :
>>
>> riakc_pb_socket:fetch_type(Pid, {BucketType, Bucket}, Key, []).
>>
>> -----------------------------------------------------------------------------------------------------------------------------
>>
>> * Step to perform an update :
>>
>> - Fetch document
>> - Update document
>>
>> -----------------------------------------------------------------------------------------------------------------------------
>>
>> * Data got from fetch_type:
>>
>> {map, [{{<<"account_id">>,register},
>> <<"accounta25a424b8484181e8ba1bec25bf7c491">>},
>> {{<<"created_by_id">>,register},
>> <<"accounta25a424b8484181e8ba1bec25bf7c491">>},
>> {{<<"created_time_dt">>,register},<<"2017-01-27T03:34:04Z">>},
>> {{<<"currency">>,register},<<"cad">>},
>> {{<<"end_time">>,register},<<"dont_use">>},
>> {{<<"id">>,register},<<"menufe89488afa948875cab6b0b18d579f21">>},
>> {{<<"maintain_mode_b">>,register},<<"false">>},
>> {{<<"menu_category_revision_id">>,register},
>> <<"0-634736bc14e0bd3ed7e3fe0f1ee64443">>},
>> {{<<"name">>,register},<<"fullmenu">>}, {{<<"order_i">>,register},<<"0">>},
>> {{<<"rest_location_p">>,register},
>> <<"10.844117421366443,106.63982392275398">>},
>> {{<<"restaurant_id">>,register},
>> <<"rest848e042b3a0488640981c8a6dc4a8281">>},
>> {{<<"restaurant_status_id">>,register},<<"inactive">>},
>> {{<<"start_time">>,register},<<"dont_use">>},
>> {{<<"status_id">>,register},<<"hide">>}, {{<<"updated_by_id">>,register},
>> <<"accounta25a424b8484181e8ba1bec25bf7c491">>},
>> {{<<"updated_time_dt">>,register},<<"2017-02-06T17:22:39Z">>}],
>> [],
>> [],
>> <<131,108,0,0,0,3,104,2,109,0,0,0,12,39,21,84,209,219,42,57,233,0,0,156,252,97,34,104,2,109,0,0,0,12,132,107,248,226,103,5,182,208,0,0,118,2,97,40,104,2,109,0,0,0,12,137,252,139,186,176,202,25,96,0,0,195,164,97,54,106>>}
>>
>>
>> * Update with update_type
>>
>> Below is Map data before using riakc_map:to_op(Map) :
>>
>> {map, [] ,
>>
>> [{{<<"account_id">>,register},{register,<<>>,<<"accounta25a424b8484181e8ba1bec25bf7c491">>}},{{<<"created_by_id">>,register},{register,<<>>,<<"accounta25a424b8484181e8ba1bec25bf7c491">>}},{{<<"created_time_dt">>,register},{register,<<>>,<<"2017-01-27T03:34:04Z">>}},{{<<"currency">>,register},{register,<<>>,<<"cad">>}},{{<<"end_time">>,register},{register,<<>>,<<"dont_use">>}},{{<<"id">>,register},{register,<<>>,<<"menufe89488afa948875cab6b0b18d579f21">>}},{{<<"maintain_mode_b">>,register},{register,<<>>,<<"false">>}},{{<<"menu_category_revision_id">>,register},{register,<<>>,<<"0-634736bc14e0bd3ed7e3fe0f1ee64443">>}},{{<<"name">>,register},{register,<<>>,<<"fullmenu">>}},{{<<"order_i">>,register},{register,<<>>,<<"0">>}},{{<<"rest_location_p">>,register},{register,<<>>,<<"10.844117421366443,106.63982392275398">>}},{{<<"restaurant_id">>,register},{register,<<>>,<<"rest848e042b3a0488640981c8a6dc4a8281">>}},{{<<"restaurant_status_id">>,register},{register,<<>>,<<"inactive">>}},{{<<"start_time">>,register},{register,<<>>,<<"dont_use">>}},{{<<"status_id">>,register},{register,<<>>,<<"show">>}},{{<<"updated_by_id">>,register},{register,<<>>,<<"accounta25a424b8484181e8ba1bec25bf7c491">>}},{{<<"updated_time_dt">>,register},{register,<<>>,<<"2017-02-06T17:22:39Z">>}}],
>>
>> [] ,
>> <<131,108,0,0,0,3,104,2,109,0,0,0,12,39,21,84,209,219,42,57,233,0,0,156,252,97,34,104,2,109,0,0,0,12,132,107,248,226,103,5,182,208,0,0,118,2,97,39,104,2,109,0,0,0,12,137,252,139,186,176,202,25,96,0,0,195,164,97,53,106>>
>> }
>>
>>
>>
>>
>> -
>>
>> Best regards,
>> Hue Tran
>> <riak.conf>_______________________________________________
>> riak-users mailing list
>> [email protected]
>> http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com
>
>
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