datastax-java-driver

I have a column family called Emails and i am saving mails into this CF, it is taking 100+seconds to write 5000 mails . I am using i3 processor, 8gb ram . My data center has 6 nodes with replication factor = 2. Does the size of the data what we store into the Cassandra affects the performance ? What are all the factors that affects write performance and how do i increase the performance ? Thanks in advance.. Jacek L. Some of factors you are asking about are: connection speed and latency between the client and the cluster, and between machines in the cluster (as mentioned by @omnibear )

I'm using Cassandra 2.1.2 with the corresponding DataStax Java driver and the Object mapping provided by DataStax. following table definition: CREATE TABLE IF NOT EXISTS ses.tim (id text PRIMARY KEY, start bigint, cid int); the mapping: @Table(keyspace = "ses", name = "tim") class MyObj { @PartitionKey private String id; private Long start; private int cid; } the accessor @Accessor interface MyAccessor { @Query("SELECT * FROM ses.tim WHERE id = :iid") MyObj get(@Param("iid") String id); @Query(SELECT * FROM ses.tim WHERE start <= :sstart") Result<MyObj> get(@Param("sstart") long start); } as

I have two table with below model: CREATE TABLE IF NOT EXISTS INV ( CODE TEXT, PRODUCT_CODE TEXT, LOCATION_NUMBER TEXT, QUANTITY DECIMAL, CHECK_INDICATOR BOOLEAN, VERSION BIGINT, PRIMARY KEY ((LOCATION_NUMBER, PRODUCT_CODE))); CREATE TABLE IF NOT EXISTS LOOK_INV ( LOCATION_NUMBER TEXT, CHECK_INDICATOR BOOLEAN, PRODUCT_CODE TEXT, CHECK_INDICATOR_DDTM TIMESTAMP, PRIMARY KEY ((LOCATION_NUMBER), CHECK_INDICATOR, PRODUCT_CODE)) WITH CLUSTERING ORDER BY (CHECK_INDICATOR ASC, PRODUCT_CODE ASC); I have a business operation where i need to update CHECK_INDICATOR in both the tables and QUANTITY in INV

I have been looking at the CQL 3.0 data modelling documentation which describes a column family of songs with tags, created like this: CREATE TABLE songs ( id uuid PRIMARY KEY, title text, tags set<text> ); I would like to get a list of all songs which have a specific tag, so I need to add an appropriate index. I can create an index on the title column easily enough, but if I try to index the tags column which is a collection, like this: CREATE INDEX ON songs ( tags ); I get the following error from the DataStax Java driver 1.0.4: Exception in thread "main" com.datastax.driver.core.exceptions

I tried with the data type blob . That's giving some Datastax exception. I tried the object itself, bytearray. Still no good: Caused by: com.datastax.driver.core.exceptions.InvalidQueryException: Invalid STRING constant ([B@547248ad) for user_object of type blob This is the failing INSERT: executeSting.append("INSERT INTO htadb.objecttable (object_id, bucket_name, object_key, link, user_status, user_object) ") .append("VALUES (") .append(objectId).append(",'") .append(bucketName).append("','") .append(key).append("','") .append(link).append("','") .append("online").append("','") .append