Member since
02-23-2016
51
Posts
96
Kudos Received
4
Solutions
My Accepted Solutions
Title | Views | Posted |
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2428 | 05-25-2016 04:42 PM | |
3616 | 05-16-2016 01:09 PM | |
1591 | 04-27-2016 05:40 PM | |
5728 | 02-26-2016 02:14 PM |
03-29-2018
01:49 PM
15 Kudos
An article on the challenges and solutions to predicting machine failures in the field. The full details can be found here: https://github.com/kirkhas/zeppelin-notebooks/tree/master/Preventive_maintenance Step #1 Feature Selection Step #2 Geolocation Step #3 - Scythe is a time-series library authored by Kirk Haslbeck for these purposes - Needed to Resample the data into trips or route segments (Scythe Resample) - Needed to Step Interpolate the miles since last service to be 4K, 5K and less continuous regression Step #4 - Indexing and OneHotEncoding to the Rescue. Found a relationship of a particular "Make" that was more problematic than most. Roc Curve - A near perfect model
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01-31-2017
04:11 PM
1 Kudo
Updating this thread. Hive has primary and foreign keys for metadata and query optimization. https://cwiki.apache.org/confluence/display/Hive/Column+Statistics+in+Hive ALTER TABLE TABLENAME ADD CONSTRAINT COLNAME_PK PRIMARY KEY (CS_ID);
ALTER TABLE TABLENAME ADD CONSTRAINT COLNAME_FK1 FOREIGN KEY (TBL_ID) REFERENCES TBLS
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01-27-2017
06:39 PM
Is there another method or workaround that can replace the "transform" method. Or suggested usage to resolve the error below. select transform(host, ip) using 'python parse_mro.py' as (host string, ip string) from table1; Error: Error while processing statement: FAILED: Hive Internal Error: org.apache.hadoop.hive.ql.security.authorization.plugin.HiveAccessControlException(Query with transform clause is disallowed in current configuration.) (state=08S01,code=12)
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Apache Hive
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Apache Ranger
11-18-2016
02:19 PM
What about Ranger, can that provide protection at this level? Assuming data does get removed any recovery options?
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11-18-2016
01:23 PM
What are the best recovery options if a product like Abinitio runs an m_rm command that deletes the HDFS data in one of the environments. These type of low level executions by-pass the Hadoop dfs rm command that puts the deleted data in the trash folder for recover. The Trash Interval is Configured for 21 Days in the Hortonworks Environment. Data had to be recreated from the source files, but if this were prod what are the best recovery options?
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Apache Hadoop
09-14-2016
01:33 PM
1 Kudo
When running hive 1.2.1 on HDP 2.4 Hive successfully connects to the metastore and then later drops the connection. It seems like an exception is throwing after it successfully connects to metastore. I noticed if we turn off the CBO settings it will by pass the metastore and skip this exception. We are using ORC and have run compute stats. 2016-09-07 04:44:08,643 INFO [main]: hive.metastore (HiveMetaStoreClient.java:isCompatibleWith(296)) - Mestastore configuration hive.metastore.filter.hook changed from org.apache.hadoop.hive.metastore.DefaultMetaStoreFilterHookImpl to org.apache.hadoop.hive.ql.security.authorization.plugin.AuthorizationMetaStoreFilterHook
2016-09-07 04:44:08,647 INFO [main]: hive.metastore (HiveMetaStoreClient.java:open(382)) - Trying to connect to metastore with URI INFO [main]: hive.metastore (HiveMetaStoreClient.java:open(478)) - Connected to metastore. -- 2016-09-07 04:44:08,647 INFO [main]: hive.metastore (HiveMetaStoreClient.java:open(382)) - Trying to connect to metastore with URI 2016-09-07 04:44:08,649 INFO [main]: hive.metastore (HiveMetaStoreClient.java:open(478)) - Connected to metastore.
2016-09-07 04:44:08,664 INFO [main]: Configuration.deprecation (Configuration.java:warnOnceIfDeprecated(1173)) - mapred.input.dir.recursive is deprecated. Instead, use mapreduce.input.fileinputformat.input.dir.recursive
2016-09-07 04:44:08,729 WARN [main]: metastore.RetryingMetaStoreClient (RetryingMetaStoreClient.java:invoke(184)) - MetaStoreClient lost connection. Attempting to reconnect.
org.apache.thrift.transport.TTransportException
at org.apache.thrift.transport.TIOStreamTransport.read(TIOStreamTransport.java:132)
at org.apache.thrift.transport.TTransport.readAll(TTransport.java:86)
at org.apache.thrift.protocol.TBinaryProtocol.readAll(TBinaryProtocol.java:429)
at org.apache.thrift.protocol.TBinaryProtocol.readI32(TBinaryProtocol.java:318)
at org.apache.thrift.protocol.TBinaryProtocol.readMessageBegin(TBinaryProtocol.java:219)
at org.apache.thrift.TServiceClient.receiveBase(TServiceClient.java:69)
at org.apache.hadoop.hive.metastore.api.ThriftHiveMetastore$Client.recv_get_aggr_stats_for(ThriftHiveMetastore.java:3033) 2016-09-07 04:44:13,784 WARN [main]: metastore.RetryingMetaStoreClient (RetryingMetaStoreClient.java:invoke(184)) - MetaStoreClient lost connection. Attempting to reconnect.
org.apache.thrift.transport.TTransportException
at org.apache.thrift.transport.TIOStreamTransport.read(TIOStreamTransport.java:132)
at org.apache.thrift.transport.TTransport.readAll(TTransport.java:86)
at org.apache.thrift.protocol.TBinaryProtocol.readAll(TBinaryProtocol.java:429)
at org.apache.thrift.protocol.TBinaryProtocol.readI32(TBinaryProtocol.java:318)
at org.apache.thrift.protocol.TBinaryProtocol.readMessageBegin(TBinaryProtocol.java:219)
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Apache Hive
09-13-2016
02:50 PM
4 Kudos
How will Spark designate resources in spark 1.6.1+ when using num-executors? This question comes up a lot so I wanted to use a baseline example. On an 8 node cluster ( 2 name nodes) (1 edge node) (5 worker nodes). Each worker node having 20 cores and 256G. if num-executors = 5 will you get 5 total executors or 5 on each node? Table below for illustration. cores executors per node executors total 25 5 25
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Apache Spark
08-29-2016
06:43 PM
Can it run both Spark 1.6.1 and Spark 2.0 or just Spark 2.0 ?
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08-24-2016
08:04 PM
7 Kudos
Brandon Wilson has a great article that shows how to use the "CACHE TABLE" cmd in Tableau, however more recent drivers have come out and you can now connect directly to the thriftserver using a spark-sql driver. This is using HDP 2.5 and SimbaSparkOdbc. First pull up a Tableau connection and select the thriftServer. Additionally had to open the virtualbox port 10015. Next if you don't have the driver Tableau will jump you to a page where you can download a spark-sql driver and inside that package chose this driver. Once you establish a valid connection you will see Tableau flag the connects based on the driver. Below you will see the Hive connection from Brandon's article and now the new Spark connection. Next using the CACHE cmd enter the below into Tableau's initial SQL box. Finally check the storage of spark for the warehouse/crimes table in memory. Or any table of your chosing for that matter. Some visuals from Tableau.
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07-06-2016
04:24 PM
4 Kudos
Query JSON using Spark
Imagine you are ingesting JSON msgs but each one has different tag names or even a different structure. This is very common because JSON is a flexible nested structure. However we commonly interact with data in a flat table like structure using SQL. The decision becomes to either parse the dynamic data into a physical schema (on write) or apply a schema at runtime (on read). Ultimately the decision will likely be made based on the number of writes vs reads. However there is one major advantage to using Spark to apply schema on read to JSON events, it alleviates the parsing step. Typically you have to hand code all the tags in the JSON msgs and map each one to a schema column. This may require meeting with upstream teams or third parties to get the DDL/xsd or schema definition. It also doesn't protect you from msgs you haven't seen or new tags being added to existing JSON structures. Sparks schema on read handles all of this as well as flattens the structure into a SQL queryable table. In the example below there are 3 different JSON msgs each with different tags and structures. If the goal is to normalize the data for a specific reporting or data science task you may be better off defining a physical schema where items like price and strikePrice are converged to a common column that makes sense in both contexts. However if your goal is to process or serve msgs like a msg bus, or if you find that it is better to query stocks separately from options because the attributes should not be interpreted and you do not want to become the author of the data you are processing then this could be an ideal approach. (A non-authoritative, low maintenance approach that is queryable) {"tradeId":"123", "assetClass":"stock", "transType":"buy", "price":"22.34",
"stockAttributes":{
"5avg":"20.12","52weekHi":"27.56"
}
}
{"tradeId":"456", "assetClass":"future", "transType":"sell", "strikePrice":"40.00",
"contractType": "forward",
"account":{
"city":"Columbus","state":"Ohio", "zip":"21000"
}
}
{"tradeId":"789", "assetClass":"option", "transType":"buy", "strikePrice":"35.75",
"account":{
"accountType":"retail","city":"Columbus","state":"Ohio"
}
}
1.0 The below image shows the 3 different JSON msgs (stock,option,future) with different attributes and structures.
2.0 Here you can query all of the data or any segment of the data using SQL.
Full code on zephub - code link
Pros: Data tags and structure are always in sync with provider No data loss No parsing layer (code effort), faster time to market No authoring, naming or defining columns Cons: SQL reads will be slower than a physically flattened and written table Deserialization cost and can't benefit from modern day columnar operations Compression - "don't use JSON" video from summit https://www.youtube.com/watch?v=tB28rPTvRiI&feature=youtu.be&t=20m3s
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