What operation are you performing? It looks like the map is a single level map
of last-write-wins registers. Are you updating a value? Is there a chance that
the time on the node handling the update is behind the value in the
lww-register?
Have you tried using the `modify_type` operation in riakc_pb_socket which does
the fetch/update operation in sequence for you?
Anything in the error logs on any of the nodes?
Is the opaque context identical from the fetch and then later after the update?
Thanks
Russell
On 6 Feb 2017, at 19:11, John Daily <jda...@basho.com> 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 <tranmyhue.grac...@gmail.com> 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: 'riak-node1@64.137.190.244'
>>
>> -----------------------------------------------------------------------------------------------------------------------------
>>
>> - 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":"riak-node1@64.137.190.244","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% -- 'riak-node1@64.137.190.244'
>> valid 18.8% -- 'riak-node2@64.137.247.82'
>> valid 18.8% -- 'riak-node3@64.137.162.64'
>> valid 25.0% -- 'riak-node4@64.137.161.229'
>> valid 18.8% -- 'riak-node5@64.137.217.73'
>> -------------------------------------------------------------------------------
>> Valid:5 / Leaving:0 / Exiting:0 / Joining:0 / Down:0
>>
>>
>> -----------------------------------------------------------------------------------------------------------------------------
>>
>> - Ring
>>
>> >> riak-admin status | grep ring
>>
>> ring_creation_size : 64
>> ring_members : ['riak-node1@64.137.190.244','riak-node2@64.137.247.82',
>> 'riak-node3@64.137.162.64','riak-node4@64.137.161.229',
>> 'riak-node5@64.137.217.73']
>> ring_num_partitions : 64
>> ring_ownership : <<"[{'riak-node2@64.137.247.82',12},\n
>> {'riak-node5@64.137.217.73',12},\n {'riak-node1@64.137.190.244',12},\n
>> {'riak-node3@64.137.162.64',12},\n {'riak-node4@64.137.161.229',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
>> riak-users@lists.basho.com
>> http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com
>
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