1. How do I measure the size of the index (cube) in version 5? You can check storage of specific Indexes from the Index page. https://kylin.apache.org/5.0/docs/modeling/model_design/aggregation_group#view-aggregate-index or https://kylin.apache.org/5.0/assets/images/index_1-6ad3f55183d4ed61962359d9408ba192.png
2. How to create the cardinality for each column? You should check this link : https://kylin.apache.org/5.0/docs/datasource/data_sampling/ . 3. In your default project sample named SSB project, you have only 4 simple aggregate group index and no table index as in attached file so what is the best strategy to select index for our OLAP? 1. There does exist a 'Base Table Index' by default actually, its id is 20000000001. 2. I think it is a good question and Kylin 5 lacks such a guide for better modeling. You are free to ask your question to mailing list and I will try to reply. ------------------------ With warm regard Xiaoxiang Yu On Wed, Nov 1, 2023 at 2:12 PM Xiaoxiang Yu <x...@apache.org> wrote: > OK, I didn't read all the mail history so I misunderstand the situation. > Looks like you need to analyse > the cause why the query didn't hit the cube correctly. > > Please generate query diagnosis package and send it to me privately. I > will analyse the query log. > You can refer to the following steps in screenshots. > > [image: image.png] > > If the screenshots are not displaying correctly, please read this guide : > > https://kylin.apache.org/5.0/docs/operations/system-operation/diagnosis/#generate-query-diagnosis-package-in-web-ui > > By the way, you need to analyse the cause by reading kylin.query.log, not > the kylin.log, > refer to https://kylin.apache.org/5.0/docs/operations/logs/system_log > > ------------------------ > With warm regard > Xiaoxiang Yu > > > > On Wed, Nov 1, 2023 at 12:18 PM Nam Đỗ Duy <na...@vnpay.vn> wrote: > >> Thank you Xiaoxiang for your advice. As my title email shown, I guessed >> that the OLAP functionalities has not been correctly set up in my computer. >> >> The evidence about it is that: when I disable the Pushdown option box to >> use solely the precomputation cube only, it showed following error: Please >> kindly advise how to properly build the OLAP >> >> LIMIT 500": No realization found for OLAPContext, MODEL_UNMATCHED_JOIN, >> rel#2240:KapTableScan.OLAP.[](table=[VNEVENT_HIVE_DWH_400MILLION_ROWS, >> FACTUSEREVENT],ctx=0@null,fields=[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, >> 13, 14, 15, 16, 17, 18, 19, 20]) >> >> >> >> On Wed, Nov 1, 2023 at 10:40 AM Xiaoxiang Yu <x...@apache.org> wrote: >> >>> Hi, >>> >>> Yesterday, I tried to see if query pushdown functions work well in >>> the Kylin5 docker, and all of my queries return proper responses . >>> After checking your logs from Shaofeng, I found these error messages >>> repeated many times: >>> 1. 'java.io.IOException: All datanodes DatanodeInfoWithStorage[ >>> 127.0.0.1:9866,DS-5093899b-06c7-4386-95d5-6fc271d92b52,DISK] are bad. >>> Aborting...' >>> 2. 'curator.ConnectionState : Connection timed out for connection >>> string (localhost:2181) and timeout (15000) / elapsed (41794) >>> org.apache.curator.CuratorConnectionLossException: KeeperErrorCode = >>> ConnectionLoss' >>> >>> I guess the root cause is that the container didn't not have enough >>> resources. I found you query on a table called >>> 'XXX_hive_dwh_400million_rows', looks like you gave a complex query on a >>> table which contains 400 million rows? >>> >>> Since I am the uploader of kylin5 's docker image, I want to give >>> some explainment. Kylin5 docker is not a place for performance benchmarks, >>> it is only for demonstration. It is only allocated with very little >>> resources(8G memory) if you are using the default command from docker hub >>> page. Before I uploaded my image, I only tested my image using the ssb >>> dataset, which the biggest table only contains about 60k rows. If you are >>> using a larger dataset and complexer queries, you have to scale the >>> resource properly. Try querying tables which contain not more than 100k >>> rows by default. >>> >>> Here are some tips which may help you to check if the daemon service >>> is in health status and resources(particularly disk space) is configured >>> properly. >>> >>> 1. Checking HDFS 's web ui( >>> http://localhost:9870/dfshealth.html#tab-datanode ) to confirm whether >>> HDFS service is in 'In service' status. >>> 2. Checking Datanode 's log in >>> `/opt/hadoop-3.2.1/logs/hadoop-root-datanode-Kylin5-Machine.log`, check if >>> there is any error message. Like: cat >>> /opt/hadoop-3.2.1/logs/hadoop-root-datanode-Kylin5-Machine.log | grep ERROR >>> | wc -l >>> 3. Checking if your docker engine is configured with enough disk >>> space, if you are using Docker Desktop like me,please go to "Settings" - >>> "Resources" - "Advanced", make sure you have allocated 40GB+ disk space to >>> the docker container. >>> 4. Checking the available disk space of your container by `df -h`, >>> make sure the 'Use%' of 'overlay' is less than 60% . >>> 5. Checking the load average/ cpu usage/ jvm gc. Make sure these >>> metrics are not really high when you send a query. >>> ------------------------ >>> With warm regard >>> Xiaoxiang Yu >>> >>> >>> >>> On Tue, Oct 31, 2023 at 5:13 PM Nam Đỗ Duy <na...@vnpay.vn.invalid> >>> wrote: >>> >>>> Hi ShaoFeng >>>> >>>> Thank you very much for your valuable feedback >>>> >>>> I saw the application to be there (if I see it right) as in the >>>> attachment photo. Kindly advise so that I can run this query on OLAP. >>>> >>>> PS. I sent you the log file in private. >>>> >>>> [image: image.png] >>>> >>>> On Tue, Oct 31, 2023 at 3:11 PM ShaoFeng Shi <shaofeng...@apache.org> >>>> wrote: >>>> >>>>> Can you provide the messages in logs/kylin.log when executing the SQL? >>>>> and you can also check the Spark UI from yarn resource manager (there >>>>> should be one running application called Spardar, which is Kylin's backend >>>>> spark application). If the application is not there, it may indicates the >>>>> yarn doesn't have resource to startup it. >>>>> >>>>> Best regards, >>>>> >>>>> Shaofeng Shi 史少锋 >>>>> Apache Kylin PMC, >>>>> Apache Incubator PMC, >>>>> Email: shaofeng...@apache.org >>>>> >>>>> Apache Kylin FAQ: >>>>> https://kylin.apache.org/docs/gettingstarted/faq.html >>>>> Join Kylin user mail group: user-subscr...@kylin.apache.org >>>>> Join Kylin dev mail group: dev-subscr...@kylin.apache.org >>>>> >>>>> >>>>> >>>>> >>>>> Nam Đỗ Duy <na...@vnpay.vn> 于2023年10月31日周二 10:35写道： >>>>> >>>>>> Dear Sir/Madam, >>>>>> >>>>>> I have a fact with 500million rows then I build model, index >>>>>> according to the website help. >>>>>> >>>>>> I chose full incremental because this is the first times I load data >>>>>> >>>>>> I create both index types Aggregate group index, table index as photo >>>>>> attached. >>>>>> >>>>>> But the query always failed after timeout of 300 seconds (I run in >>>>>> docker), I dont want to increase the value of 300 seconds because I wish >>>>>> the OLAP can run within 1 minutes (is that possible?) >>>>>> >>>>>> It seems that the OLAP function in indexing not working to speedup >>>>>> the query by precomputed cube. >>>>>> >>>>>> Can you advise to check whether the index did really work? >>>>>> >>>>>> It is quite urgent task for me so prompt response is highly >>>>>> appreciated. >>>>>> >>>>>> Thank you very much >>>>>> >>>>>
