= Bulk Loading

Bulk loading Apache Cassandra data is supported by different tools.
The data to bulk load must be in the form of SSTables.
Cassandra does not support loading data in any other format such as CSV,
JSON, and XML directly.
Although the cqlsh `COPY` command can load CSV data, it is not a good option
for amounts of data.
Bulk loading is used to:

* Restore incremental backups and snapshots. Backups and snapshots are
already in the form of SSTables.
* Load existing SSTables into another cluster. The data can have a
different number of nodes or replication strategy.
* Load external data to a cluster.

== Tools for Bulk Loading

Cassandra provides two commands or tools for bulk loading data:

* Cassandra Bulk loader, also called `sstableloader`
* The `nodetool import` command

The `sstableloader` and `nodetool import` are accessible if the
Cassandra installation `bin` directory is in the `PATH` environment
variable.
Or these may be accessed directly from the `bin` directory.
The examples use the keyspaces and tables created in xref:cassandra:managing/operating/backups.adoc[Backups].

== Using sstableloader

The `sstableloader` is the main tool for bulk uploading data.
`sstableloader` streams SSTable data files to a running cluster,
conforming to the replication strategy and replication factor.
The table to upload data to does need not to be empty.

The only requirements to run `sstableloader` are:

* One or more comma separated initial hosts to connect to and get ring
information
* A directory path for the SSTables to load

[source,bash]
----
sstableloader [options] <dir_path>
----

Sstableloader bulk loads the SSTables found in the directory
`<dir_path>` to the configured cluster.
The `<dir_path>` is used as the target _keyspace/table_ name.
For example, to load an SSTable named `Standard1-g-1-Data.db` into `Keyspace1/Standard1`,
you will need to have the files `Standard1-g-1-Data.db` and `Standard1-g-1-Index.db` in a
directory `/path/to/Keyspace1/Standard1/`.

=== Sstableloader Option to accept Target keyspace name

Often as part of a backup strategy, some Cassandra DBAs store an entire data directory.
When corruption in the data is found, restoring data in the same cluster (for large clusters 200 nodes)
is common, but with a different keyspace name.

Currently `sstableloader` derives keyspace name from the folder structure.
As an option, to specify target keyspace name as part of `sstableloader`,
version 4.0 adds support for the `--target-keyspace` option
(https://issues.apache.org/jira/browse/CASSANDRA-13884[CASSANDRA-13884]).

The following options are supported, with `-d,--nodes <initial hosts>` required:

[source,none]
----
-alg,--ssl-alg <ALGORITHM>                                   Client SSL: algorithm

-ap,--auth-provider <auth provider>                          Custom
                                                             AuthProvider class name for
                                                             cassandra authentication
-ciphers,--ssl-ciphers <CIPHER-SUITES>                       Client SSL:
                                                             comma-separated list of
                                                             encryption suites to use
-cph,--connections-per-host <connectionsPerHost>             Number of
                                                             concurrent connections-per-host.
-d,--nodes <initial hosts>                                   Required.
                                                             Try to connect to these hosts (comma separated) initially for ring information

--entire-sstable-throttle-mib <throttle-mib>                 Entire SSTable throttle
                                                             speed in MiB/s (default 0 for unlimited).

--entire-sstable-inter-dc-throttle-mib                       <inter-dc-throttle-mib>
                                                             Entire SSTable inter-datacenter throttle
                                                             speed in MiB/s (default 0 for unlimited).

-f,--conf-path <path to config file>                         cassandra.yaml file path for streaming throughput and client/server SSL.

-h,--help                                                    Display this help message

-i,--ignore <NODES>                                          Don't stream to this (comma separated) list of nodes

-idct,--inter-dc-throttle <inter-dc-throttle>                (deprecated) Inter-datacenter throttle speed in Mbits (default 0 for unlimited).
                                                             Use --inter-dc-throttle-mib instead.

--inter-dc-throttle-mib <inter-dc-throttle-mib>              Inter-datacenter throttle speed in MiB/s (default 0 for unlimited)

-k,--target-keyspace <target keyspace name>                  Target
                                                             keyspace name
-ks,--keystore <KEYSTORE>                                    Client SSL:
                                                             full path to keystore
-kspw,--keystore-password <KEYSTORE-PASSWORD>                Client SSL:
                                                             password of the keystore
--no-progress                                                Don't
                                                             display progress
-p,--port <native transport port>                            Port used
                                                             for native connection (default 9042)
-prtcl,--ssl-protocol <PROTOCOL>                             Client SSL:
                                                             connections protocol to use (default: TLS)
-pw,--password <password>                                    Password for
                                                             cassandra authentication
-sp,--storage-port <storage port>                            Port used
                                                             for internode communication (default 7000)
-spd,--server-port-discovery <allow server port discovery>   Use ports
                                                             published by server to decide how to connect. With SSL requires StartTLS
                                                             to be used.
-ssp,--ssl-storage-port <ssl storage port>                   Port used
                                                             for TLS internode communication (default 7001)
-st,--store-type <STORE-TYPE>                                Client SSL:
                                                             type of store
-t,--throttle <throttle>                                     (deprecated) Throttle speed in Mbits (default 0 for unlimited).
                                                             Use --throttle-mib instead.
--throttle-mib <throttle-mib>                                Throttle
                                                             speed in MiB/s (default 0 for unlimited)
-ts,--truststore <TRUSTSTORE>                                Client SSL:
                                                             full path to truststore
-tspw,--truststore-password <TRUSTSTORE-PASSWORD>            Client SSL:
                                                             Password of the truststore
-u,--username <username>                                     Username for
                                                             cassandra authentication
-v,--verbose                                                 verbose
                                                             output
----

The `cassandra.yaml` file can be provided on the command-line with `-f` option to set up streaming throughput, client and server encryption
options.
Only `stream_throughput_outbound_megabits_per_sec`, `server_encryption_options` and `client_encryption_options` are read
from the `cassandra.yaml` file.
You can override options read from `cassandra.yaml` with corresponding command line options.

=== A sstableloader Demo

An example shows how to use `sstableloader` to upload incremental backup data for the table `catalogkeyspace.magazine`.
In addition, a snapshot of the same table is created to bulk upload, also with `sstableloader`.

The backups and snapshots for the `catalogkeyspace.magazine` table are listed as follows:

[source,bash]
----
$ cd ./cassandra/data/data/catalogkeyspace/magazine-446eae30c22a11e9b1350d927649052c && ls -l
----

results in

[source,none]
----
total 0
drwxrwxr-x. 2 ec2-user ec2-user 226 Aug 19 02:38 backups
drwxrwxr-x. 4 ec2-user ec2-user  40 Aug 19 02:45 snapshots
----

The directory path structure of SSTables to be uploaded using
`sstableloader` is used as the target keyspace/table.
You can directly upload from the `backups` and `snapshots`
directories respectively, if the directory structure is in the format
used by `sstableloader`.
But the directory path of backups and snapshots for SSTables is
`/catalogkeyspace/magazine-446eae30c22a11e9b1350d927649052c/backups` and
`/catalogkeyspace/magazine-446eae30c22a11e9b1350d927649052c/snapshots`
respectively, and cannot be used to upload SSTables to
`catalogkeyspace.magazine` table.
The directory path structure must be `/catalogkeyspace/magazine/` to use `sstableloader`.
Create a new directory structure to upload SSTables with `sstableloader`
located at `/catalogkeyspace/magazine` and set appropriate permissions.

[source,bash]
----
$ sudo mkdir -p /catalogkeyspace/magazine
$ sudo chmod -R 777 /catalogkeyspace/magazine
----

==== Bulk Loading from an Incremental Backup

An incremental backup does not include the DDL for a table; the table must already exist.
If the table was dropped, it can be created using the `schema.cql` file generated with every snapshot of a table.
Prior to using `sstableloader` to load SSTables to the `magazine` table, the table must exist.
The table does not need to be empty but we have used an empty table as indicated by a CQL query:

[source,cql]
----
SELECT * FROM magazine;
----
results in
[source,cql]
----
id | name | publisher
----+------+-----------

(0 rows)
----

After creating the table to upload to, copy the SSTable files from the `backups` directory to the `/catalogkeyspace/magazine/` directory.

[source,bash]
----
$ sudo cp ./cassandra/data/data/catalogkeyspace/magazine-446eae30c22a11e9b1350d927649052c/backups/* \
/catalogkeyspace/magazine/
----

Run the `sstableloader` to upload SSTables from the
`/catalogkeyspace/magazine/` directory.

[source,bash]
----
$ sstableloader --nodes 10.0.2.238  /catalogkeyspace/magazine/
----

The output from the `sstableloader` command should be similar to this listing:

[source,bash]
----
$ sstableloader --nodes 10.0.2.238  /catalogkeyspace/magazine/
----

results in

[source,none]
----
Opening SSTables and calculating sections to stream
Streaming relevant part of /catalogkeyspace/magazine/na-1-big-Data.db
/catalogkeyspace/magazine/na-2-big-Data.db  to [35.173.233.153:7000, 10.0.2.238:7000,
54.158.45.75:7000]
progress: [35.173.233.153:7000]0:1/2 88 % total: 88% 0.018KiB/s (avg: 0.018KiB/s)
progress: [35.173.233.153:7000]0:2/2 176% total: 176% 33.807KiB/s (avg: 0.036KiB/s)
progress: [35.173.233.153:7000]0:2/2 176% total: 176% 0.000KiB/s (avg: 0.029KiB/s)
progress: [35.173.233.153:7000]0:2/2 176% [10.0.2.238:7000]0:1/2 39 % total: 81% 0.115KiB/s
(avg: 0.024KiB/s)
progress: [35.173.233.153:7000]0:2/2 176% [10.0.2.238:7000]0:2/2 78 % total: 108%
97.683KiB/s (avg: 0.033KiB/s)
progress: [35.173.233.153:7000]0:2/2 176% [10.0.2.238:7000]0:2/2 78 %
[54.158.45.75:7000]0:1/2 39 % total: 80% 0.233KiB/s (avg: 0.040KiB/s)
progress: [35.173.233.153:7000]0:2/2 176% [10.0.2.238:7000]0:2/2 78 %
[54.158.45.75:7000]0:2/2 78 % total: 96% 88.522KiB/s (avg: 0.049KiB/s)
progress: [35.173.233.153:7000]0:2/2 176% [10.0.2.238:7000]0:2/2 78 %
[54.158.45.75:7000]0:2/2 78 % total: 96% 0.000KiB/s (avg: 0.045KiB/s)
progress: [35.173.233.153:7000]0:2/2 176% [10.0.2.238:7000]0:2/2 78 %
[54.158.45.75:7000]0:2/2 78 % total: 96% 0.000KiB/s (avg: 0.044KiB/s)
----

After the `sstableloader` has finished loading the data, run a query the `magazine` table to check:

[source,cql]
----
SELECT * FROM magazine;
----
results in
[source,cql]
----
id | name                      | publisher
----+---------------------------+------------------
 1 |        Couchbase Magazine |        Couchbase
 0 | Apache Cassandra Magazine | Apache Cassandra

(2 rows)
----

==== Bulk Loading from a Snapshot

Restoring a snapshot of a table to the same table can be easily accomplished:

If the directory structure needed to load SSTables to `catalogkeyspace.magazine` does not exist create the
directories and set appropriate permissions:

[source,bash]
----
$ sudo mkdir -p /catalogkeyspace/magazine
$ sudo chmod -R 777 /catalogkeyspace/magazine
----

Remove any files from the directory, so that the snapshot files can be copied without interference:

[source,bash]
----
$ sudo rm /catalogkeyspace/magazine/*
$ cd /catalogkeyspace/magazine/
$ ls -l
----

results in

[source,none]
----
total 0
----

Copy the snapshot files to the `/catalogkeyspace/magazine` directory.

[source,bash]
----
$ sudo cp ./cassandra/data/data/catalogkeyspace/magazine-446eae30c22a11e9b1350d927649052c/snapshots/magazine/* \
/catalogkeyspace/magazine
----

List the files in the `/catalogkeyspace/magazine` directory.
The `schema.cql` will also be listed.

[source,bash]
----
$ cd /catalogkeyspace/magazine && ls -l
----

results in

[source,none]
----
total 44
-rw-r--r--. 1 root root   31 Aug 19 04:13 manifest.json
-rw-r--r--. 1 root root   47 Aug 19 04:13 na-1-big-CompressionInfo.db
-rw-r--r--. 1 root root   97 Aug 19 04:13 na-1-big-Data.db
-rw-r--r--. 1 root root   10 Aug 19 04:13 na-1-big-Digest.crc32
-rw-r--r--. 1 root root   16 Aug 19 04:13 na-1-big-Filter.db
-rw-r--r--. 1 root root   16 Aug 19 04:13 na-1-big-Index.db
-rw-r--r--. 1 root root 4687 Aug 19 04:13 na-1-big-Statistics.db
-rw-r--r--. 1 root root   56 Aug 19 04:13 na-1-big-Summary.db
-rw-r--r--. 1 root root   92 Aug 19 04:13 na-1-big-TOC.txt
-rw-r--r--. 1 root root  815 Aug 19 04:13 schema.cql
----

Alternatively create symlinks to the snapshot folder instead of copying
the data:

[source,bash]
----
$ mkdir <keyspace_name>
$ ln -s <path_to_snapshot_folder> <keyspace_name>/<table_name>
----

If the `magazine` table was dropped, run the DDL in the `schema.cql` to
create the table.
Run the `sstableloader` with the following command:

[source,bash]
----
$ sstableloader --nodes 10.0.2.238  /catalogkeyspace/magazine/
----

As the output from the command indicates, SSTables get streamed to the
cluster:

[source,none]
----
Established connection to initial hosts
Opening SSTables and calculating sections to stream
Streaming relevant part of /catalogkeyspace/magazine/na-1-big-Data.db  to
[35.173.233.153:7000, 10.0.2.238:7000, 54.158.45.75:7000]
progress: [35.173.233.153:7000]0:1/1 176% total: 176% 0.017KiB/s (avg: 0.017KiB/s)
progress: [35.173.233.153:7000]0:1/1 176% total: 176% 0.000KiB/s (avg: 0.014KiB/s)
progress: [35.173.233.153:7000]0:1/1 176% [10.0.2.238:7000]0:1/1 78 % total: 108% 0.115KiB/s
(avg: 0.017KiB/s)
progress: [35.173.233.153:7000]0:1/1 176% [10.0.2.238:7000]0:1/1 78 %
[54.158.45.75:7000]0:1/1 78 % total: 96% 0.232KiB/s (avg: 0.024KiB/s)
progress: [35.173.233.153:7000]0:1/1 176% [10.0.2.238:7000]0:1/1 78 %
[54.158.45.75:7000]0:1/1 78 % total: 96% 0.000KiB/s (avg: 0.022KiB/s)
progress: [35.173.233.153:7000]0:1/1 176% [10.0.2.238:7000]0:1/1 78 %
[54.158.45.75:7000]0:1/1 78 % total: 96% 0.000KiB/s (avg: 0.021KiB/s)
----

Some other requirements of `sstableloader` that should be kept into
consideration are:

* The SSTables loaded must be compatible with the Cassandra
version being loaded into.
* Repairing tables that have been loaded into a different cluster does
not repair the source tables.
* Sstableloader makes use of port 7000 for internode communication.
* Before restoring incremental backups, run `nodetool flush` to backup
any data in memtables.

== Using nodetool import

Importing SSTables into a table using the `nodetool import` command is recommended instead of the deprecated
`nodetool refresh` command.
The `nodetool import` command has an option to load new SSTables from a separate directory.

The command usage is as follows:

[source,none]
----
nodetool [(-h <host> | --host <host>)] [(-p <port> | --port <port>)]
       [(-pp | --print-port)] [(-pw <password> | --password <password>)]
       [(-pwf <passwordFilePath> | --password-file <passwordFilePath>)]
       [(-u <username> | --username <username>)] import
       [(-c | --no-invalidate-caches)] [(-e | --extended-verify)]
       [(-l | --keep-level)] [(-q | --quick)] [(-r | --keep-repaired)]
       [(-t | --no-tokens)] [(-v | --no-verify)] [--] <keyspace> <table>
       <directory> ...
----

The arguments `keyspace`, `table` name and `directory` are required.

The following options are supported:

[source,none]
----
-c, --no-invalidate-caches
    Don't invalidate the row cache when importing

-e, --extended-verify
    Run an extended verify, verifying all values in the new SSTables

-h <host>, --host <host>
    Node hostname or ip address

-l, --keep-level
    Keep the level on the new SSTables

-p <port>, --port <port>
    Remote jmx agent port number

-pp, --print-port
    Operate in 4.0 mode with hosts disambiguated by port number

-pw <password>, --password <password>
    Remote jmx agent password

-pwf <passwordFilePath>, --password-file <passwordFilePath>
    Path to the JMX password file

-q, --quick
    Do a quick import without verifying SSTables, clearing row cache or
    checking in which data directory to put the file

-r, --keep-repaired
    Keep any repaired information from the SSTables

-t, --no-tokens
    Don't verify that all tokens in the new SSTable are owned by the
    current node

-u <username>, --username <username>
    Remote jmx agent username

-v, --no-verify
    Don't verify new SSTables

--
    This option can be used to separate command-line options from the
    list of argument, (useful when arguments might be mistaken for
    command-line options
----

Because the keyspace and table are specified on the command line for
`nodetool import`, there is not the same requirement as with
`sstableloader`, to have the SSTables in a specific directory path.
When importing snapshots or incremental backups with
`nodetool import`, the SSTables don’t need to be copied to another
directory.

=== Importing Data from an Incremental Backup

Using `nodetool import` to import SSTables from an incremental backup, and restoring
the table is shown below.

[source,cql]
----
DROP table t;
----

An incremental backup for a table does not include the schema definition for the table.
If the schema definition is not kept as a separate
backup, the `schema.cql` from a backup of the table may be used to
create the table as follows:

[source,cql]
----
CREATE TABLE IF NOT EXISTS cqlkeyspace.t (
   id int PRIMARY KEY,
   k int,
   v text)
   WITH ID = d132e240-c217-11e9-bbee-19821dcea330
   AND bloom_filter_fp_chance = 0.01
   AND crc_check_chance = 1.0
   AND default_time_to_live = 0
   AND gc_grace_seconds = 864000
   AND min_index_interval = 128
   AND max_index_interval = 2048
   AND memtable_flush_period_in_ms = 0
   AND speculative_retry = '99p'
   AND additional_write_policy = '99p'
   AND comment = ''
   AND caching = { 'keys': 'ALL', 'rows_per_partition': 'NONE' }
   AND compaction = { 'max_threshold': '32', 'min_threshold': '4',
   'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy' }
   AND compression = { 'chunk_length_in_kb': '16', 'class':
   'org.apache.cassandra.io.compress.LZ4Compressor' }
   AND cdc = false
   AND extensions = {  }
;
----

Initially the table could be empty, but does not have to be.

[source,cql]
----
SELECT * FROM t;
----
[source,cql]
----
id | k | v
----+---+---

(0 rows)
----

Run the `nodetool import` command, providing the keyspace, table and
the backups directory.
Don’t copy the table backups to another directory, as with `sstableloader`.

[source,bash]
----
$ nodetool import -- cqlkeyspace t \
./cassandra/data/data/cqlkeyspace/t-d132e240c21711e9bbee19821dcea330/backups
----

The SSTables are imported into the table. Run a query in cqlsh to check:

[source,cql]
----
SELECT * FROM t;
----
[source,cql]
----
id | k | v
----+---+------
 1 | 1 | val1
 0 | 0 | val0

(2 rows)
----

=== Importing Data from a Snapshot

Importing SSTables from a snapshot with the `nodetool import` command is
similar to importing SSTables from an incremental backup.
Shown here is an import of a snapshot for table `catalogkeyspace.journal`, after
dropping the table to demonstrate the restore.

[source,cql]
----
USE CATALOGKEYSPACE;
DROP TABLE journal;
----

Use the `catalog-ks` snapshot for the `journal` table.
Check the files in the snapshot, and note the existence of the `schema.cql` file.

[source,bash]
----
$ ls -l
----
[source,none]
----
total 44
-rw-rw-r--. 1 ec2-user ec2-user   31 Aug 19 02:44 manifest.json
-rw-rw-r--. 3 ec2-user ec2-user   47 Aug 19 02:38 na-1-big-CompressionInfo.db
-rw-rw-r--. 3 ec2-user ec2-user   97 Aug 19 02:38 na-1-big-Data.db
-rw-rw-r--. 3 ec2-user ec2-user   10 Aug 19 02:38 na-1-big-Digest.crc32
-rw-rw-r--. 3 ec2-user ec2-user   16 Aug 19 02:38 na-1-big-Filter.db
-rw-rw-r--. 3 ec2-user ec2-user   16 Aug 19 02:38 na-1-big-Index.db
-rw-rw-r--. 3 ec2-user ec2-user 4687 Aug 19 02:38 na-1-big-Statistics.db
-rw-rw-r--. 3 ec2-user ec2-user   56 Aug 19 02:38 na-1-big-Summary.db
-rw-rw-r--. 3 ec2-user ec2-user   92 Aug 19 02:38 na-1-big-TOC.txt
-rw-rw-r--. 1 ec2-user ec2-user  814 Aug 19 02:44 schema.cql
----

Copy the DDL from the `schema.cql` and run in cqlsh to create the
`catalogkeyspace.journal` table:

[source,cql]
----
CREATE TABLE IF NOT EXISTS catalogkeyspace.journal (
   id int PRIMARY KEY,
   name text,
   publisher text)
   WITH ID = 296a2d30-c22a-11e9-b135-0d927649052c
   AND bloom_filter_fp_chance = 0.01
   AND crc_check_chance = 1.0
   AND default_time_to_live = 0
   AND gc_grace_seconds = 864000
   AND min_index_interval = 128
   AND max_index_interval = 2048
   AND memtable_flush_period_in_ms = 0
   AND speculative_retry = '99p'
   AND additional_write_policy = '99p'
   AND comment = ''
   AND caching = { 'keys': 'ALL', 'rows_per_partition': 'NONE' }
   AND compaction = { 'min_threshold': '4', 'max_threshold':
   '32', 'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy' }
   AND compression = { 'chunk_length_in_kb': '16', 'class':
   'org.apache.cassandra.io.compress.LZ4Compressor' }
   AND cdc = false
   AND extensions = {  }
;
----

Run the `nodetool import` command to import the SSTables for the
snapshot:

[source,bash]
----
$ nodetool import -- catalogkeyspace journal \
./cassandra/data/data/catalogkeyspace/journal-
296a2d30c22a11e9b1350d927649052c/snapshots/catalog-ks/
----

Subsequently run a CQL query on the `journal` table to check the imported data:

[source,cql]
----
SELECT * FROM journal;
----
[source,cql]
----
id | name                      | publisher
----+---------------------------+------------------
 1 |        Couchbase Magazine |        Couchbase
 0 | Apache Cassandra Magazine | Apache Cassandra

(2 rows)
----

== Bulk Loading External Data

Bulk loading external data directly is not supported by any of the tools
we have discussed which include `sstableloader` and `nodetool import`.
The `sstableloader` and `nodetool import` require data to be in the form
of SSTables.
Apache Cassandra supports a Java API for generating SSTables from input data, using the
`org.apache.cassandra.io.sstable.CQLSSTableWriter` Java class.
Subsequently, either `sstableloader` or `nodetool import` is used to bulk load the SSTables.

=== Generating SSTables with CQLSSTableWriter Java API

To generate SSTables using the `CQLSSTableWriter` class the following are required:

* An output directory to generate the SSTable in
* The schema for the SSTable
* A prepared statement for the `INSERT`
* A partitioner

The output directory must exist before starting. Create a directory
(`/sstables` as an example) and set appropriate permissions.

[source,bash]
----
$ sudo mkdir /sstables
$ sudo chmod  777 -R /sstables
----

To use `CQLSSTableWriter` in a Java application, create a Java constant for the output directory.

[source,java]
----
public static final String OUTPUT_DIR = "./sstables";
----

`CQLSSTableWriter` Java API can create a user-defined type. Create a new type to store `int` data:

[source,java]
----
String type = "CREATE TYPE CQLKeyspace.intType (a int, b int)";
// Define a String variable for the SSTable schema.
String schema = "CREATE TABLE CQLKeyspace.t ("
                 + "  id int PRIMARY KEY,"
                 + "  k int,"
                 + "  v1 text,"
                 + "  v2 intType,"
                 + ")";
----

Define a `String` variable for the prepared statement to use:

[source,java]
----
String insertStmt = "INSERT INTO CQLKeyspace.t (id, k, v1, v2) VALUES (?, ?, ?, ?)";
----

The partitioner to use only needs setting if the default partitioner `Murmur3Partitioner` is not used.

All these variables or settings are used by the builder class
`CQLSSTableWriter.Builder` to create a `CQLSSTableWriter` object.

Create a File object for the output directory.

[source,java]
----
File outputDir = new File(OUTPUT_DIR + File.separator + "CQLKeyspace" + File.separator + "t");
----

Obtain a `CQLSSTableWriter.Builder` object using `static` method `CQLSSTableWriter.builder()`.
Set the following items:

* output directory `File` object
* user-defined type
* SSTable schema
* buffer size
* prepared statement
* optionally any of the other builder options

and invoke the `build()` method to create a `CQLSSTableWriter` object:

[source,java]
----
CQLSSTableWriter writer = CQLSSTableWriter.builder()
                                             .inDirectory(outputDir)
                                             .withType(type)
                                             .forTable(schema)
                                             .withBufferSizeInMB(256)
                                             .using(insertStmt).build();
----

Set the SSTable data. If any user-defined types are used, obtain a
`UserType` object for each type:

[source,java]
----
UserType userType = writer.getUDType("intType");
----

Add data rows for the resulting SSTable:

[source,java]
----
writer.addRow(0, 0, "val0", userType.newValue().setInt("a", 0).setInt("b", 0));
   writer.addRow(1, 1, "val1", userType.newValue().setInt("a", 1).setInt("b", 1));
   writer.addRow(2, 2, "val2", userType.newValue().setInt("a", 2).setInt("b", 2));
----

Close the writer, finalizing the SSTable:

[source,java]
----
writer.close();
----

Other public methods the `CQLSSTableWriter` class provides are:

[cols=",",options="header",]
|===
|Method |Description

|addRow(java.util.List<java.lang.Object> values) |Adds a new row to the
writer. Returns a CQLSSTableWriter object. Each provided value type
should correspond to the types of the CQL column the value is for. The
correspondence between java type and CQL type is the same one than the
one documented at
www.datastax.com/drivers/java/2.0/apidocs/com/datastax/driver/core/DataType.Name.html#asJavaC
lass().

|addRow(java.util.Map<java.lang.String,java.lang.Object> values) |Adds a
new row to the writer. Returns a CQLSSTableWriter object. This is
equivalent to the other addRow methods, but takes a map whose keys are
the names of the columns to add instead of taking a list of the values
in the order of the insert statement used during construction of this
SSTable writer. The column names in the map keys must be in lowercase
unless the declared column name is a case-sensitive quoted identifier in
which case the map key must use the exact case of the column. The values
parameter is a map of column name to column values representing the new
row to add. If a column is not included in the map, it's value will be
null. If the map contains keys that do not correspond to one of the
columns of the insert statement used when creating this SSTable writer,
the corresponding value is ignored.

|addRow(java.lang.Object... values) |Adds a new row to the writer.
Returns a CQLSSTableWriter object.

|CQLSSTableWriter.builder() |Returns a new builder for a
CQLSSTableWriter.

|close() |Closes the writer.

|rawAddRow(java.nio.ByteBuffer... values) |Adds a new row to the writer
given already serialized binary values. Returns a CQLSSTableWriter
object. The row values must correspond to the bind variables of the
insertion statement used when creating by this SSTable writer.

|rawAddRow(java.util.List<java.nio.ByteBuffer> values) |Adds a new row
to the writer given already serialized binary values. Returns a
CQLSSTableWriter object. The row values must correspond to the bind
variables of the insertion statement used when creating by this SSTable
writer.

|rawAddRow(java.util.Map<java.lang.String, java.nio.ByteBuffer> values)
|Adds a new row to the writer given already serialized binary values.
Returns a CQLSSTableWriter object. The row values must correspond to the
bind variables of the insertion statement used when creating by this
SSTable writer.

|getUDType(String dataType) |Returns the User Defined type used in this
SSTable Writer that can be used to create UDTValue instances.
|===

Other public methods the `CQLSSTableWriter.Builder` class provides are:

[cols=",",options="header",]
|===
|Method |Description
|inDirectory(String directory) |The directory where to write the
SSTables. This is a mandatory option. The directory to use should
already exist and be writable.

|inDirectory(File directory) |The directory where to write the SSTables.
This is a mandatory option. The directory to use should already exist
and be writable.

|forTable(String schema) |The schema (CREATE TABLE statement) for the
table for which SSTable is to be created. The provided CREATE TABLE
statement must use a fully-qualified table name, one that includes the
keyspace name. This is a mandatory option.

|withPartitioner(IPartitioner partitioner) |The partitioner to use. By
default, Murmur3Partitioner will be used. If this is not the partitioner
used by the cluster for which the SSTables are created, the correct
partitioner needs to be provided.

|using(String insert) |The INSERT or UPDATE statement defining the order
of the values to add for a given CQL row. The provided INSERT statement
must use a fully-qualified table name, one that includes the keyspace
name. Moreover, said statement must use bind variables since these
variables will be bound to values by the resulting SSTable writer. This
is a mandatory option.

|withBufferSizeInMiB(int size) |The size of the buffer to use. This
defines how much data will be buffered before being written as a new
SSTable. This corresponds roughly to the data size that will have the
created SSTable. The default is 128MB, which should be reasonable for a
1GB heap. If OutOfMemory exception gets generated while using the
SSTable writer, should lower this value.

|withBufferSizeInMB(int size) |Deprecated, and it will be available
at least until next major release. Please use withBufferSizeInMiB(int size)
which is the same method with a new name.

|sorted() |Creates a CQLSSTableWriter that expects sorted inputs. If
this option is used, the resulting SSTable writer will expect rows to be
added in SSTable sorted order (and an exception will be thrown if that
is not the case during row insertion). The SSTable sorted order means
that rows are added such that their partition keys respect the
partitioner order. This option should only be used if the rows can be
provided in order, which is rarely the case. If the rows can be provided
in order however, using this sorted might be more efficient. If this
option is used, some option like withBufferSizeInMB will be ignored.

|build() |Builds a CQLSSTableWriter object.
|===
