Source: https://dev-docs.nebula-graph.io/v5.3.2/utilities/exchange/export-data/
Documentation version: v5.3.2

# Export data with NebulaGraph Exchange

Use NebulaGraph Exchange to export a graph to files or to another graph. The source and destination graphs may be in the same NebulaGraph Database Developer Edition cluster or in different clusters.

## Prerequisites

- [Deploy NebulaGraph Exchange](https://dev-docs.nebula-graph.io/v5.3.2/utilities/exchange/deploy-exchange/).
- Start the source NebulaGraph Database Developer Edition service group. See [Quick start](https://dev-docs.nebula-graph.io/v5.3.2/get-started/deploy/).
- If exporting to another cluster, start its destination service group as well.

## Run an export

1. 

In the `nebula-graph-exchange/` directory, start Spark:

````
./start.sh

````

The script prints the process IDs of the Spark master and workers when they start successfully.

2. 

In the same directory, run `export.sh`:

````
./export.sh [ -f | -g ] -c "<export_parameters>"

````

Use `-f` to [export to files](https://dev-docs.nebula-graph.io/v5.3.2/utilities/exchange/export-data/#export-to-files) or `-g` to [export to a graph](https://dev-docs.nebula-graph.io/v5.3.2/utilities/exchange/export-data/#export-to-a-graph). Both modes require `-c` with the relevant export parameters.

 | Option | Description | Required | Default
 | `-f` | Export to files. Required if `-g` is omitted. | No | None
 | `-g` | Export to NebulaGraph Database Developer Edition. Required if `-f` is omitted. | No | None
 | `-c` | Export parameters; see the sections below. | Yes | None
 | `-j` | Path to the NebulaGraph Exchange JAR. | No | `nebula-exchange-5.3.0.jar`
 | `-m` | Maximum memory per job. | No | `1G`
 | `-n` | Number of export jobs. | No | `20`
 | `-p` | CPU cores used in parallel per job. | No | `5`
 | `-P` | Spark server port. | No | `1077`
 | `-h` | Print help. | No | None
 | `-s` | Spark home directory, if you use your own Spark installation. | No | None
 | `-o` | Spark master mode when using your own Spark installation. | No | None

Set `n × p` lower than `c × i`, where `c` and `i` are the values set during [NebulaGraph Exchange deployment](https://dev-docs.nebula-graph.io/v5.3.2/utilities/exchange/deploy-exchange/).

3. 

Wait for the export to finish. For a file export, the output includes a log path and a completion message:

````
start to export data to file...
logging to /home/user/tmp/nebula-graph-exchange/logs/export_to_file.log
25/05/06 18:21:37 INFO Nebula2File$: >>>>> finished the export! cost: 15.743s.

````

For an export to another graph, the corresponding log is `export_to_nebula.log`:

````
start to export data to nebula...
logging to /home/user/tmp/nebula-graph-exchange/logs/export_to_nebula.log
25/05/06 18:21:37 INFO Nebula2Nebula$: >>>>> finished the sync! cost: 15.743s.

````

4. 

Check the result. For files, inspect the location specified by `--writePath`. For a graph export, query the destination graph at `--targetGraphAddress`. If the result is unexpected, inspect the log named above for the chosen mode.

## Export parameter reference

Pass export parameters as a double-quoted value of `-c`.

### Export to files

For example:

Replace `<source-password>` and `<target-password>` with the current passwords for the source and target accounts, respectively. If a password has changed, use the new password.

````
./export.sh -f -c "-sourceGraph 127.0.0.1:9669 -sourceGraphName movie -sourceGraphType movie_type -sourcePasswd <source-password> -path file:///tmp/export1/"

````

 | Option | Alias | Description | Required | Default
 | `--excludeEdges` | `-excludeEdges` | Edge types to exclude, separated by commas. | No | None
 | `--excludeNodes` | `-excludeNodes` | Node types to exclude, separated by commas. | No | None
 | `--format` | `-f` | File format: `csv`, `txt`, or `json`. | No | `csv`
 | `--header` | `-h` | Write a header row in CSV files: `true` or `false`. | No | `true`
 | `--includeNode` | `-includeNode` | Export only this node type, useful for testing. | No | None
 | `--writePath` | `-path` | Destination path. Use `hdfs://` for HDFS or `file:///` for a local file system. | Yes | None
 | `--readBatchSize` | `-readBatchSize` | Batch size for read requests. | No | None
 | `--sep` | `-s` | Field separator in CSV files. | No | Comma
 | `--sourceGraphAddress` | `-sourceGraph` | Source Graph service addresses, separated by commas. | Yes | None
 | `--sourceGraphName` | `-sourceGraphName` | Source graph name. | Yes | None
 | `--sourceGraphType` | `-sourceGraphType` | Source graph type. | Yes | None
 | `--sourceGraphPassword` | `-sourcePasswd` | Password for the source Graph service. | Yes | None
 | `--sourceSchema` | `-sourceSchema` | Source Schema path. | No | None
 | `--sourceGraphUser` | `-sourceUser` | Username for the source Graph service. | No | `root`
 | `--timeout` | `-timeout` | Client timeout in seconds. Requests exceeding it are cancelled. | No | `5`

### Export to a graph

For example:

````
./export.sh -g -c "-sourceGraph 127.0.0.1:9669 -sourceGraphName movie -sourceGraphType movie_type -sourcePasswd <source-password> -targetGraph 127.0.0.1:9669 -targetGraphName movie1 -targetPasswd <target-password>"

````

 | Option | Alias | Description | Required | Default
 | `--excludeEdges` | `-excludeEdges` | Edge types to exclude, separated by commas. | No | None
 | `--excludeNodes` | `-excludeNodes` | Node types to exclude, separated by commas. | No | None
 | `--includeNode` | `-includeNode` | Export only this node type, useful for testing. | No | None
 | `--mode` | `-m` | Write mode. All modes insert nodes and edges that do not exist. For existing nodes and edges, `insert` fails the export and reports an error; `insert_ignore` ignores the write and keeps existing data unchanged without reporting an error; `insert_replace` replaces them with the submitted data; `insert_update` updates them with the submitted property values. See [INSERT](https://dev-docs.nebula-graph.io/v5.3.2/database-gql-reference/dml/insert/#insert-modes). | No | `insert_ignore`
 | `--parallel` | `-p` | Write parallelism. `-1` matches the NebulaGraph Database Developer Edition partition parallelism; see [SHOW PARTITIONS](https://dev-docs.nebula-graph.io/v5.3.2/database-gql-reference/data-admin/show/show-partitions/). | No | `-1`
 | `--readBatchSize` | `-readBatchSize` | Batch size for read requests. | No | None
 | `--sourceGraphAddress` | `-sourceGraph` | Source Graph service addresses, separated by commas. | Yes | None
 | `--sourceGraphName` | `-sourceGraphName` | Source graph name. | Yes | None
 | `--sourceGraphType` | `-sourceGraphType` | Source graph type. | Yes | None
 | `--sourceGraphPassword` | `-sourcePasswd` | Password for the source Graph service. | Yes | None
 | `--sourceSchema` | `-sourceSchema` | Source Schema path. | No | None
 | `--sourceGraphUser` | `-sourceUser` | Username for the source Graph service. | No | `root`
 | `--targetGraphAddress` | `-targetGraph` | Destination Graph service addresses, separated by commas. | Yes | None
 | `--targetGraphName` | `-targetGraphName` | Destination graph name; if omitted, uses the source graph name. | No | None
 | `--targetGraphType` | `-targetGraphType` | Destination graph type; if omitted, uses the source graph type. | No | None
 | `--targetGraphPassword` | `-targetPasswd` | Password for the destination Graph service. | Yes | None
 | `--targetSchema` | `-targetSchema` | Destination Schema path. | No | None
 | `--targetUser` | `-targetUser` | Username for the destination Graph service. | No | `root`
 | `--timeout` | `-timeout` | Client timeout in seconds. Requests exceeding it are cancelled. | No | `5`
 | `--writeBatchSize` | `-writeBatchSize` | Batch size for write requests. | No | None