I have a Local directory it is used to store the hive table data.
I need to list all tables which are using Local directory .
These tables (managed tables) are stored in hive Default DB , this DB allows to store Data in other Local directories .
My Local directory : /abc/efg/data/
Table data is Stored in sub folders like 123 , 456,789 etc
For table xyz location is /abc/efg/data/123 , PQR location is /abc/efg/data/456 like that.
I am trying to use
hive -e " show tables " > All_tables list all tables and redirect to a file
For each line(each table) in All_tables
hive -e " desc formatted $line " | grep '/abc/efg/data/' >> Tables_My_local_dir
but it will result some performance issue as i have 6000 tables in DB .
please help me to list all tables which are using Local directory with a best performance.
I assume that you wanted to list table and its corresponding location information by extracting it from the desc formatted command for managed tables in default database.
If my understanding is correct, I suggest you to go with querying the Hive Meta-store, provided its an externally configured one and you have necessary permissions to fetch the same information
Query on meta-store:
SELECT T.TBL_NAME AS TABLE_NAME,S.LOCATION AS LOCATION FROM TBLS T LEFT JOIN SDS S ON T.SD_ID=S.SD_ID WHERE T.TBL_TYPE='MANAGED_TABLE' AND T.DB_ID=1 ;
note: in the query, DB_ID for default database is 1
Output:
------------+------------------------------------------------------------+
| TABLE_NAME | LOCATION |
+------------+------------------------------------------------------------+
| sample | hdfs://********:8020/user/hive/warehouse/sample |
...
.
Based on the rule
HADOOP TABLES ARE DIRECTORIES
I have created a shell script to do the below steps.
Step 1. Find all the directories which are not being modified since last 14 days .
Step 2 . Separate real tables and real folders 2.1execute "desc $dir_name "
2.2 based on return status($？) redirect $dir_name to two files(one for real tables and other for directories )
Now I have the required tables in a file.
Related
Im new to hadoop etc.
Connect via beeline to hiveserver2. Then I create table:
create table test02(id int, name string);
Table creates and I try to insert values:
insert into test02(id, name) values (1, "user1");
And nothing happens. table02 and values__tmp__table__1 are created but they are both empty.
Hadoop directory "/user/$username/warehouse/test01" is empty to.
0: jdbc:hive2://localhost:10000> insert into test02 values (1,"user1");
No rows affected (2.284 seconds)
0: jdbc:hive2://localhost:10000> select * from test02;
+------------+--------------+
| test02.id | test02.name |
+------------+--------------+
+------------+--------------+
No rows selected (0.326 seconds)
0: jdbc:hive2://localhost:10000> show tables;
+------------------------+
| tab_name |
+------------------------+
| test02 |
| values__tmp__table__1 |
+------------------------+
2 rows selected (0.137 seconds)
Temp tables like these are created when hive needs to manage intermediate data during an operation. Hive automatically deletes all temporary tables at the end of the Hive session in which they are created. If you close the session and open it again, you won't find the temp table.
https://docs.cloudera.com/HDPDocuments/HDP2/HDP-2.5.0/bk_data-access/content/temp-tables.html
Insert data like this ->
insert into test02 values (999, "user_new");
Data would be inserted into test02 and a temp table like values__tmp__table__1 (temp table will gone after the hive session).
I found a solution. I'm new to Hadoop&co, so the answer was not obvious to me.
First, I turned Hive logging to level ERROR to see the problem:
Find hive-exec-log4j2.properties ({your hive directory}/conf/)
Find property.hive.log.level and set the value to ERROR (..log.level = ERROR)
Then, while executing the command insert into via Beeline, I saw all of the errors. The main error was:
There are 0 datanode(s) running and no node(s) are excluded in this operation
I found the same question elsewhere. The top answer helped me, which was to delete all /tmp/* files (which stored all of my local HDFS data).
Then, like the first time, I initialized namenode (-format) and Hive (ran my metahive script).
The problem was solved—though it did expose another issue, which I'll need to look into: the insert into executes in 25+ seconds.
I am trying to create timestamp based partition in hive. But hive is creating data based partition. Below is my code. Could someone please help?
cat test1.sh
dat=`date +'%Y%m%d %H:%m:%S'`
hive -f load.hql -hiveconf file_load_timestamp=$dat;
cat load.hql
INSERT OVERWRITE table perm.test partition(file_load_timestamp='${hiveconf:dat}')
SELECT a,b FROM work.temp;
dt=20180102/ = HDFS path is getting created like this.
dt=20180102 103455/ = Expecting HDFS path to be created like this.
When I tried with %Y%m%d_%H:%m:%S' format its working as expected. But I need space between date and timestamp.
To create a folder name in HDFS with space in between, it is required to escape the space with \
hadoop fs -mkdir test\ 123
create a folder in hdfs with name test 123.
Similarly, hive maintains the partitions in folders created with the partition value. Thats why providing the date format %Y%m%d\ %H%m%S will help to create folder with spaces.
Below is tested and working:
INSERT OVERWRITE table person_details1 partition(datelocal='20180102\ 200128') select * from person_details;
datelocal is String
Edited:Executed the code, Below is working one:
hduser#Amit:~$ cat test1.sh
#!/bin/sh
dat=`date +'%Y%m%d\ %H%m%S'`
hive -f load.hql -hiveconf datelocal="$dat";
hduser#Amit:~$ cat load.hql
INSERT OVERWRITE table amit.person_details1 partition(datelocal='${hiveconf:datelocal}') select * from amit.person_details;
I started an EC2 cluster on amazon to install cloudera...I got it installed and configured and loaded some of the Wiki Page Views public snapshot into HDFS. The structure of the files are as such:
projectcode, pagename, pageviews, bytes
the files are named as such:
pagecounts-20090430-230000.gz
date time
when loading the data from HDFS to Impala, I do it as such:
CREATE EXTERNAL TABLE wikiPgvws
(
project_code varchar(100),
page_name varchar(1000),
page_views int,
page_bytes int
)
ROW FORMAT DELIMITED FIELDS TERMINATED BY ' '
LOCATION '/user/hdfs';
one thing I missed is the date and time of each of the file. The dir:
/user/hdfs
contains multiple pagecount files associated with different dates and times. How can one pull that information and store it in a column when loading to impala?
I think the thing you are missing is the concept of partitions. If you define the table as partitioned, the data may be divided to different partitions based on the timestamp(in the name) of the file. I'm able to work around it in hive, I hope you to do the needful(if any) for impala as there query syntax is the same.
For me, this problem is not possible to solve only using hive. So I mixed up bash with hive scripting and it works fine for me. This is how I wrapped it up :
Create table wikiPgvws with partition
Create table wikiTmp with same fields as wikiPgvws except for partitions
For each file
i. Load data into wikiTmp
ii. grep timeStamp from fileName
iii. Use sed to replace placeholders in a predefined hql script file to load the data to the actual table. Then run it.
Drop table wikiTmp & remove tmp.hql
The script is as follows :
#!/bin/bash
hive -e "CREATE EXTERNAL TABLE wikiPgvws(
project_code varchar(100),
page_name varchar(1000),
page_views int,
page_bytes int
)
PARTITIONED BY(dts STRING)
ROW FORMAT DELIMITED FIELDS TERMINATED BY ' '
STORED AS TEXTFILE";
hive -e "CREATE TABLE wikiTmp(
project_code varchar(100),
page_name varchar(1000),
page_views int,
page_bytes int
)
ROW FORMAT DELIMITED FIELDS TERMINATED BY ' '
STORED AS TEXTFILE"
for fileName in $(hadoop fs -ls /user/hdfs/bounty/pagecounts-*.txt | grep -Po '(?<=\s)(/user.*$)')
do
echo "currentFile :$fileName"
dst=$(echo $filename | grep -oE '[0-9]{8}-[0-9]{6}')
echo "currentStamp $dst"
sed "s!sourceFile!'$fileName'!" t.hql > tmp.hql
sed -i "s!targetPartition!$dst!" tmp.hql
hive -f tmp.hql
done
hive -e "DROP TABLE wikiTmp"
rm -f tmp.hql
The hql script consists of just two lines :
LOAD DATA INPATH sourceFile OVERWRITE INTO TABLE wikiTmp;
INSERT OVERWRITE TABLE wikiPgvws PARTITION (dts = 'targetPartition') SELECT w.* FROM wikiTmp w;
Epilogue :
Check, whether options equivalent to hive -e & hive -f are available in impala. Without them, this script is of no use to you. Again the grep commands to fetch the fileName & timeStamp need to be modified according to your table location and stamp pattern. It's just one a way to show how the job can be done, but couldn't able to find another one.
Enhencement
If everything works well, consider merging the first two DDLs into another script to make it look cleaner. Although, I'm not sure that hql script arguments can be used to define partition values, still you can have a look to replace sed.
I have data in HDFS. And I wanted to load that data into hbase and hive table.
I have written a bash shell script in which I have written a pig script to load the data form HDFS to HBASE and also written hive script to load the data from HDFS to HIVE table which are working perfectly fine.Here my HDFS data files are with the same structure and I'm loading all the data files into single hbase and hive table.
Now my query is suppose if I receive some more data files in HDFS directory and if I run the shell script again it will create hbase and hive table again with the same name and tells table already exists. How can I write a hive and hbase query so that 1st it will check for the table existence, if table does not exists it create the table for the 1st time and load the data from HDFS to HBASE & Hive table. If the table is already exists then it will just insert the data into an existing hbase and hive table. It should not overwrite the data alreday exists in the tables.
How this can be done ?
Below is my script file: myScript.sh
echo "create 'goodtable','gt'" | hbase shell
pig -f a.pig -param input=/user/user/d/
hive -f h.hql
Where a.pig :
G = LOAD '$input' USING PigStorage(',') as (c1:chararray, c2:chararray,c3:chararray,c4:chararray,c5:chararray);
STORE G INTO 'hbase://goodtable' USING org.apache.pig.backend.hadoop.hbase.HBaseStorage('gt:name gt:state gt:phone_no gt:gender');
h.hql:
create external table hive_table(
id int,
name string,
state string,
phone_no int,
gender string) row format delimited fields terminated by ',' stored as textfile;
LOAD DATA INPATH '/user/user/d/' INTO TABLE hive_table;
I just wanted to add an example for HBase as Hive was already covered before:
if [[ $(echo "exists 'goodtable'" | hbase shell | grep 'not exist') ]];
then
echo "create 'goodtable','gt'" | hbase shell;
fi
For HIVE, you can add the command IF NOT EXISTS in the CREATE TABLE statement. See the documentation
I don't have much experience on Hbase, but I believe you can use EXISTS table_name command to check whether the table exists and then create the table is it doesn't exist. See here
#visakh is correct - you can see if table exists in HBase by entering the HBase shell, and typing : exists '<tablename>
In order to do this without entering the HBase shell interactively, you can create a simple ruby script such as the following:
exists 'mytable'
exit
Let's say you save this to a file called tabletest.rb. You can then execute this script by calling hbase shell tabletest.rb. This will create the following output, which you can then parse from your shell script:
Table tableisthere does exist
0 row(s) in 0.9830 seconds
OR
Table tableisNOTthere does not exist
0 row(s) in 0.9830 seconds
Adding more details for 'all in one' script:
Alternatively, you can create a more advanced script in ruby that checks for table existence and then will create it if needed - this is done calling the HBaseAdmin java api from within the ruby script.
conf = HBaseConfiguration.new
hbaseAdmin = HBaseAdmin.new(conf)
if !hbaseAdmin.tableExists('mytable')
hbaseAdmin.createTable('mytable',...)
end
I ran the below create script and it created the table:-
Create writable external table FLTR (like dbname.FLTR)
LOCATION ('gpfdist://172.90.38.190:8081/fltr.out')
FORMAT 'CSV' (DELIMITER ',' NULL '')
DISTRIBUTED BY (fltr_key);
But when I tried inserting into the file like insert into fltr.out select * from dbname.fltr
I got the below error, cannot find server connection.
Please help me out
I think your gpfdist is probably not running try:
gpfdist -p 8081 -l ~/gpfdist.log -d ~/ &
on 172.90.38.190.
This will start gpfidist using your home directory as the data directory.
When I do that my inserts work and create a file ~/fltr.out