Menggunakan HCatalog

Anda dapat menggunakan HCatalog dalam berbagai aplikasi yang menggunakan metastore Hive. Contoh dalam bagian ini menunjukkan cara membuat tabel dan menggunakannya dalam konteks Pig dan Spark SQL.

Nonaktifkan penulisan langsung saat menggunakan HCatalog HStorer

Setiap kali aplikasi menggunakan H CatStorer untuk menulis ke tabel HCatalog yang disimpan di Amazon S3, nonaktifkan fitur tulis langsung Amazon EMR. Misalnya, nonaktifkan penulisan langsung saat menggunakan perintah Pig STORE atau ketika menjalankan tugas Sqoop yang menulis tabel HCatalog untuk Amazon S3. Anda dapat menonaktifkan fitur penulisan langsung dengan menetapkan mapred.output.direct.NativeS3FileSystem dan mapred.output.direct.EmrFileSystem konfigurasi ke false. Contoh berikut menunjukkan cara mengatur konfigurasi ini menggunakan Java.

Configuration conf = new Configuration(); 
conf.set("mapred.output.direct.NativeS3FileSystem", "false"); 
conf.set("mapred.output.direct.EmrFileSystem", "false");

Buat tabel menggunakan HCat CLI dan gunakan data dalam Pig

Buat skrip berikut, impressions.q, di klaster Anda:

CREATE EXTERNAL TABLE impressions (
    requestBeginTime string, adId string, impressionId string, referrer string, 
    userAgent string, userCookie string, ip string
  )
  PARTITIONED BY (dt string)
  ROW FORMAT 
    serde 'org.apache.hive.hcatalog.data.JsonSerDe'
    with serdeproperties ( 'paths'='requestBeginTime, adId, impressionId, referrer, userAgent, userCookie, ip' )
  LOCATION 's3://[your region].elasticmapreduce/samples/hive-ads/tables/impressions/';
ALTER TABLE impressions ADD PARTITION (dt='2009-04-13-08-05');

Eksekusi skrip menggunakan HCat CLI:

% hcat -f impressions.q
Logging initialized using configuration in file:/etc/hive/conf.dist/hive-log4j.properties
OK
Time taken: 4.001 seconds
OK
Time taken: 0.519 seconds

Buka Grunt shell dan akses data dalam impressions:

% pig -useHCatalog -e "A = LOAD 'impressions' USING org.apache.hive.hcatalog.pig.HCatLoader(); 
B = LIMIT A 5; 
dump B;"
<snip>
(1239610346000,m9nwdo67Nx6q2kI25qt5On7peICfUM,omkxkaRpNhGPDucAiBErSh1cs0MThC,cartoonnetwork.com,Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; FunWebProducts; GTB6; SLCC1; .NET CLR 2.0.50727; Media Center PC 5.0; .NET,wcVWWTascoPbGt6bdqDbuWTPPHgOPs,69.191.224.234,2009-04-13-08-05)
(1239611000000,NjriQjdODgWBKnkGJUP6GNTbDeK4An,AWtXPkfaWGOaNeL9OOsFU8Hcj6eLHt,cartoonnetwork.com,Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; GTB6; .NET CLR 1.1.4322),OaMU1F2gE4CtADVHAbKjjRRks5kIgg,57.34.133.110,2009-04-13-08-05)
(1239610462000,Irpv3oiu0I5QNQiwSSTIshrLdo9cM1,i1LDq44LRSJF0hbmhB8Gk7k9gMWtBq,cartoonnetwork.com,Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1; .NET CLR 1.1.4322; InfoPath.1),QSb3wkLR4JAIut4Uq6FNFQIR1rCVwU,42.174.193.253,2009-04-13-08-05)
(1239611007000,q2Awfnpe0JAvhInaIp0VGx9KTs0oPO,s3HvTflPB8JIE0IuM6hOEebWWpOtJV,cartoonnetwork.com,Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1; .NET CLR 1.1.4322; InfoPath.1),QSb3wkLR4JAIut4Uq6FNFQIR1rCVwU,42.174.193.253,2009-04-13-08-05)
(1239610398000,c362vpAB0soPKGHRS43cj6TRwNeOGn,jeas5nXbQInGAgFB8jlkhnprN6cMw7,cartoonnetwork.com,Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; GTB6; .NET CLR 1.1.4322),k96n5PnUmwHKfiUI0TFP0TNMfADgh9,51.131.29.87,2009-04-13-08-05)
7120 [main] INFO  org.apache.pig.Main  - Pig script completed in 7 seconds and 199 milliseconds (7199 ms)
16/03/08 23:17:10 INFO pig.Main: Pig script completed in 7 seconds and 199 milliseconds (7199 ms)

Mengakses tabel menggunakan Spark SQL

Contoh ini membuat Spark DataFrame dari tabel yang dibuat pada contoh pertama dan menunjukkan 20 baris pertama:

% spark-shell --jars /usr/lib/hive-hcatalog/share/hcatalog/hive-hcatalog-core-1.0.0-amzn-3.jar
<snip>
scala> val hiveContext = new org.apache.spark.sql.hive.HiveContext(sc);
scala> val df = hiveContext.sql("SELECT * FROM impressions")
scala> df.show()
<snip>
16/03/09 17:18:46 INFO DAGScheduler: ResultStage 0 (show at <console>:32) finished in 10.702 s
16/03/09 17:18:46 INFO DAGScheduler: Job 0 finished: show at <console>:32, took 10.839905 s
+----------------+--------------------+--------------------+------------------+--------------------+--------------------+--------------+----------------+
|requestbegintime|                adid|        impressionid|          referrer|           useragent|          usercookie|            ip|              dt|
+----------------+--------------------+--------------------+------------------+--------------------+--------------------+--------------+----------------+
|   1239610346000|m9nwdo67Nx6q2kI25...|omkxkaRpNhGPDucAi...|cartoonnetwork.com|Mozilla/4.0 (comp...|wcVWWTascoPbGt6bd...|69.191.224.234|2009-04-13-08-05|
|   1239611000000|NjriQjdODgWBKnkGJ...|AWtXPkfaWGOaNeL9O...|cartoonnetwork.com|Mozilla/4.0 (comp...|OaMU1F2gE4CtADVHA...| 57.34.133.110|2009-04-13-08-05|
|   1239610462000|Irpv3oiu0I5QNQiwS...|i1LDq44LRSJF0hbmh...|cartoonnetwork.com|Mozilla/4.0 (comp...|QSb3wkLR4JAIut4Uq...|42.174.193.253|2009-04-13-08-05|
|   1239611007000|q2Awfnpe0JAvhInaI...|s3HvTflPB8JIE0IuM...|cartoonnetwork.com|Mozilla/4.0 (comp...|QSb3wkLR4JAIut4Uq...|42.174.193.253|2009-04-13-08-05|
|   1239610398000|c362vpAB0soPKGHRS...|jeas5nXbQInGAgFB8...|cartoonnetwork.com|Mozilla/4.0 (comp...|k96n5PnUmwHKfiUI0...|  51.131.29.87|2009-04-13-08-05|
|   1239610600000|cjBTpruoaiEtqLuMX...|XwlohBSs8Ipxs1bRa...|cartoonnetwork.com|Mozilla/4.0 (comp...|k96n5PnUmwHKfiUI0...|  51.131.29.87|2009-04-13-08-05|
|   1239610804000|Ms3eJHNAEItpxvimd...|4SIj4pGmgVLl625BD...|cartoonnetwork.com|Mozilla/4.0 (comp...|k96n5PnUmwHKfiUI0...|  51.131.29.87|2009-04-13-08-05|
|   1239610872000|h5bccHX6wJReDi1jL...|EFAWIiBdVfnxwAMWP...|cartoonnetwork.com|Mozilla/4.0 (comp...|k96n5PnUmwHKfiUI0...|  51.131.29.87|2009-04-13-08-05|
|   1239610365000|874NBpGmxNFfxEPKM...|xSvE4XtGbdtXPF2Lb...|cartoonnetwork.com|Mozilla/5.0 (Maci...|eWDEVVUphlnRa273j...| 22.91.173.232|2009-04-13-08-05|
|   1239610348000|X8gISpUTSqh1A5reS...|TrFblGT99AgE75vuj...|       corriere.it|Mozilla/4.0 (comp...|tX1sMpnhJUhmAF7AS...|   55.35.44.79|2009-04-13-08-05|
|   1239610743000|kbKreLWB6QVueFrDm...|kVnxx9Ie2i3OLTxFj...|       corriere.it|Mozilla/4.0 (comp...|tX1sMpnhJUhmAF7AS...|   55.35.44.79|2009-04-13-08-05|
|   1239610812000|9lxOSRpEi3bmEeTCu...|1B2sff99AEIwSuLVV...|       corriere.it|Mozilla/4.0 (comp...|tX1sMpnhJUhmAF7AS...|   55.35.44.79|2009-04-13-08-05|
|   1239610876000|lijjmCf2kuxfBTnjL...|AjvufgUtakUFcsIM9...|       corriere.it|Mozilla/4.0 (comp...|tX1sMpnhJUhmAF7AS...|   55.35.44.79|2009-04-13-08-05|
|   1239610941000|t8t8trgjNRPIlmxuD...|agu2u2TCdqWP08rAA...|       corriere.it|Mozilla/4.0 (comp...|tX1sMpnhJUhmAF7AS...|   55.35.44.79|2009-04-13-08-05|
|   1239610490000|OGRLPVNGxiGgrCmWL...|mJg2raBUpPrC8OlUm...|       corriere.it|Mozilla/4.0 (comp...|r2k96t1CNjSU9fJKN...|   71.124.66.3|2009-04-13-08-05|
|   1239610556000|OnJID12x0RXKPUgrD...|P7Pm2mPdW6wO8KA3R...|       corriere.it|Mozilla/4.0 (comp...|r2k96t1CNjSU9fJKN...|   71.124.66.3|2009-04-13-08-05|
|   1239610373000|WflsvKIgOqfIE5KwR...|TJHd1VBspNcua0XPn...|       corriere.it|Mozilla/5.0 (Maci...|fj2L1ILTFGMfhdrt3...| 75.117.56.155|2009-04-13-08-05|
|   1239610768000|4MJR0XxiVCU1ueXKV...|1OhGWmbvKf8ajoU8a...|       corriere.it|Mozilla/5.0 (Maci...|fj2L1ILTFGMfhdrt3...| 75.117.56.155|2009-04-13-08-05|
|   1239610832000|gWIrpDiN57i3sHatv...|RNL4C7xPi3tdar2Uc...|       corriere.it|Mozilla/5.0 (Maci...|fj2L1ILTFGMfhdrt3...| 75.117.56.155|2009-04-13-08-05|
|   1239610789000|pTne9k62kJ14QViXI...|RVxJVIQousjxUVI3r...|        pixnet.net|Mozilla/5.0 (Maci...|1bGOKiBD2xmui9OkF...| 33.176.101.80|2009-04-13-08-05|
+----------------+--------------------+--------------------+------------------+--------------------+--------------------+--------------+----------------+
only showing top 20 rows


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