Am trying to export a Cassandra Keyspace plus Data to a file. Is there a cqlsh command that allows the export of all tables + Data at once.?
I used this code to export the keyspace. Now I would like to export all the Data from all the tables into the file.
$ cqlsh -e "DESCRIBE KEYSPACE somekeyspace" > /path/to/somekeyspace.cql
Looking at the DataStax documentation, you should be able to do that using the COPY command as follows (for a single table):
COPY someKeySpace.someTable (someCol1, someCol2)
TO '/path/to/someTable_Col1Col2.csv' WITH HEADER = TRUE;
For all tables, probably you will need to write this code multiple times OR iterate through the tables. You might find this article also useful.
ps. I also found this GitHub repo that seems interesting, but I haven't used it yet myself, so I am suggesting it here for you to maybe give it a try :)
https://github.com/masumsoft/cassandra-exporter
Related
Does MemSQL support user variables in the load data command, similar to MySQL (see MySQL load NULL values from CSV data for examples)? The MemSQL documentation (https://docs.memsql.com/docs/load-data) doesn't give a clue, and my attempts at using user variables have failed.
No, variables in LOAD DATA are not currently supported in general (as of MemSQL 5.5). This is a feature we are tracking for a future release.
We only support the following syntax to skip the contents of a column in the file using a dummy variable (briefly mentioned in the docs https://docs.memsql.com/docs/load-data):
load data infile 'foo.tsv' into table foo (bar, #, #, baz);
I used the sstableloader many times successfully, but I got the following error:
[root#localhost pengcz]# /usr/local/cassandra/bin/sstableloader -u user -pw password -v -d 172.21.0.131 ./currentdata/keyspace/table
Could not retrieve endpoint ranges:
java.lang.IllegalArgumentException
java.lang.RuntimeException: Could not retrieve endpoint ranges:
at org.apache.cassandra.tools.BulkLoader$ExternalClient.init(BulkLoader.java:338)
at org.apache.cassandra.io.sstable.SSTableLoader.stream(SSTableLoader.java:156)
at org.apache.cassandra.tools.BulkLoader.main(BulkLoader.java:106)
Caused by: java.lang.IllegalArgumentException
at java.nio.Buffer.limit(Buffer.java:267)
at org.apache.cassandra.utils.ByteBufferUtil.readBytes(ByteBufferUtil.java:543)
at org.apache.cassandra.serializers.CollectionSerializer.readValue(CollectionSerializer.java:124)
at org.apache.cassandra.serializers.MapSerializer.deserializeForNativeProtocol(MapSerializer.java:101)
at org.apache.cassandra.serializers.MapSerializer.deserializeForNativeProtocol(MapSerializer.java:30)
at org.apache.cassandra.serializers.CollectionSerializer.deserialize(CollectionSerializer.java:50)
at org.apache.cassandra.db.marshal.AbstractType.compose(AbstractType.java:68)
at org.apache.cassandra.cql3.UntypedResultSet$Row.getMap(UntypedResultSet.java:287)
at org.apache.cassandra.config.CFMetaData.fromSchemaNoTriggers(CFMetaData.java:1833)
at org.apache.cassandra.config.CFMetaData.fromThriftCqlRow(CFMetaData.java:1126)
at org.apache.cassandra.tools.BulkLoader$ExternalClient.init(BulkLoader.java:330)
... 2 more
I don't know whether this error is relative to one of cluster nodes' linux crash?
Any advice will be appreciated!
Are you running different version sstable loader than the version of your cluster? Looks like https://issues.apache.org/jira/browse/CASSANDRA-9324 if using the 2.1 loader on 2.0 cluster.
/usr/local/cassandra/bin/sstableloader -u user -pw password -v -d 172.21.0.131 ./currentdata/keyspace/table into this command as mention by you backup dir is as ./currentdata/keyspace/table, change the parent directory name of table dir to the keyspace name into which you are restoring, at the place of keyspace and also change the name of table dir as these two are cassandra preserved delimeters and sstableloader consider the parent dir of backup directory(here parent->keyspace and backup-dir->table) as a keyspace name, So it should be same as the keyspace name into which you are restoring the data. Apart from this please make sure your table name and keyspace name should not be as cassandra preserved delimiters.
I realise this is an old question but I'm posting the answer here for posterity. It looks like you're hitting CASSANDRA-10700.
TL;DR - When sstableloader tries to read the schema, it fails when it comes across a dropped collections column.
The problem only exists in the sstableloader utility and you can easily workaround it by getting a copy from Cassandra 2.1.13+ as documented here. Cheers!
I need to get a dump(with data) from remote Cassandra database. I was able to get database schema via following command.How can i get all data in the keyspace?
I'm using Cassandra 1.1.9
echo -e "connect localhost/9260;\r\n use PWC_Keyspace;\r\n show schema;\n" | bin/cassandra-cli -h localhost -port 9260 > dilshan.cdl
With Cassandra 1.1.9, I don't believe you have access to cqlsh with the copy-to command, so you'll be stuck with 2 options.
1) Export the data from the data files (sstables) on disk using sstable2json, or
2) Write a program to iterate over every row and copy/serialize it to a format you find easier to work with.
You MAY be able to use a more recent cqlsh (say, from 2.0, which still used thrift instead of the native interface), and point it at your 1.1.9 server and use 'COPY TO' to export each table to a csv. However, the COPY command in cqlsh for 2.0 doesn't use paging, and cassandra 1.1.19 doesn't support paging, so there's a very good chance it's simply going to time out and fail.
I'm trying to connect to a Datastax Community Edition server 2.1.2 via JDBC but I keep getting the following error no matter what I try to do, even when issuing a very basic command like select * from system_traces.events;
InvalidRequestException(why:Keyspace 'keyspace1' does not exist)
Issuing that same command via cqlsh works properly, so it seems to be a JDBC issue.
InvalidRequestException(why:Keyspace 'keyspace1' does not exist)
at org.apache.cassandra.cql.jdbc.CassandraConnection.<init>(CassandraConnection.java:229):229
at org.apache.cassandra.cql.jdbc.CassandraDriver.connect(CassandraDriver.java:92):92
at java.sql.DriverManager.getConnection(DriverManager.java:664):664
at java.sql.DriverManager.getConnection(DriverManager.java:270):270
at railo.commons.db.DBUtil.getConnection(DBUtil.java:109):109
at railo.runtime.db.DatasourceConnectionPool.loadDatasourceConnection(DatasourceConnectionPool.java:89):89
at railo.runtime.db.DatasourceConnectionPool.getDatasourceConnection(DatasourceConnectionPool.java:81):81
at railo.runtime.db.DatasourceManagerImpl.getConnection(DatasourceManagerImpl.java:65):65
at railo.runtime.tag.Query.executeDatasoure(Query.java:696):696 ...
Any ideas? TIA!
InvalidRequestException(why:Keyspace 'keyspace1' does not exist)
This exception means you are trying to query for a keyspace (in this case "Keyspace1") that hasn't yet been added to Cassandra. Try creating the keyspace before querying it.
You're probably doing a select (SELECT * FROM "Keyspace1"."Standard1") that you're not seeing or passing initialisation parameters to JDBC telling it to connect to Keyspace1. Verify that your code isn't looking for the non-existent keyspace by searching through the queries you have, specifically looking for Keyspace1 (or "Keyspace1" since in this case the keyspace name is case-sensitive).
On a side-note, "Keyspace1"."Standard1" tend to be the standard ks.cf pair used for cassandra examples so it would be good to scan your code for them to make sure that they are created before they are queried.
the example may include:
create keyspace and columnfamily
insert data
select/get data and show in Console
because I found this http://cassandra.apache.org/doc/cql/CQL.html is hard to me
thank you for attention , I got it http://niranjandubey.blogspot.com/2012/11/cassandra-jdbc-to-perform-crud.html.
But I also need a FILE-read-write example of cassandra (may be using datastax?)