> For the complete documentation index, see [llms.txt](https://docs.streambased.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.streambased.io/deploy-and-operate/streambased-platform/hyperstream/configurations.md).
# Configurations
Streambased K.S.I. is configured by the standard Kroxylicious configuration scheme [here](https://kroxylicious.io/documentation/0.18.0/html/kroxylicious-proxy/#assembly-configuring-proxy-proxy) or by equivalent environment variables documented here:
#### Environment Variables
```properties
KSI_BOOTSTRAP_SERVERS
```
Bootstrap servers for the underlying Kafka cluster
* Type: string
* Example:
```
KSI_BOOTSTRAP_SERVERS=kafka1:9092
```
***
```properties
KSI_GATEWAY_BOOTSTRAP_ADDRESS
```
The address that clients should connect to to access the proxy.
* Type: string
* Example:
```json
KSI_GATEWAY_BOOTSTRAP_ADDRESS=ksi:9192
```
***
```properties
KSI_COLD_STORAGE_TYPE
```
The method in which K.S.I. will interact with Iceberg, supported values are:
\* spark-connect
\* iceberg
* Type: string
* Example:
```json
KSI_COLD_STORAGE_TYPE=spark-connect
```
***
```properties
KSI_SPARK_CONNECT_URL
```
The Url of Spark-Connect, this should only be used when `KSI_COLD_STORAGE_TYPE` is `spark-connect`.
* Type: string
* Example:
```json
KSI_SPARK_CONNECT_URL=sc://spark-iceberg:15002
```
***
```properties
KSI_MAX_COLD_STORAGE_RECORDS_PER_FETCH
```
The maximum number of Iceberg records to return for any signle FETCH response.
* Type: integer
* Example:
KSI_MAX_COLD_STORAGE_RECORDS_PER_FETCH=1000
***
```properties
KSI_COLD_STORAGE_TIMEOUT_MS
```
The maximum time K.S.I. will wait for records from Iceberg before returning to Kroxylicious
* Type: integer
* Example:
```
KSI_COLD_STORAGE_TIMEOUT_MS=30000
```
***
```properties
KSI_ALWAYS_RETURN_MINUS_ONE_START_OFFSET=true
```
The type of Iceberg catalog used to provide coldset data. Vendor managed catalogs have different auth, metadata column renames etc.\
Supported types are:\
\* default - Minio + Rest catalog with Sigv4 authentication\
\* iceberg-rest-fixture - Minio + Rest Catalog implemented by Iceberg Rest Fixture - Sigv4 auth, requires metadata.json relocation on Coldset / Merged set proxying\
\* tableflow - Confluent Tableflow with Confluent managed Iceberg Catalog and storage\
\* snowflake - Snowflake managed Iceberg
* Type: string
* Example:
```
coldset.client.coldset-type=tableflow
```
* Environment Variable: `ISK_COLDSET_CLIENT_COLDSET-TYPE`
***
```properties
coldset.client.coldset-ns
```
Iceberg namespace to use for Coldset
* Type: string
* Example:
```
coldset.client.coldset-ns=COLDSET
```
* Environment Variable: `ISK_COLDSET_CLIENT_COLDSET-NS`
***
```properties
coldset.client.coldset-ns
```
Iceberg namespace to use for Coldset
* Type: string
* Example:
```
coldset.client.coldset-ns=COLDSET
```
* Environment Variable: `ISK_COLDSET_CLIENT_COLDSET-NS`
```properties
schema-registry.url
```
A Schema Registry REST endpoint Streambased I.S.K. can fetch topic schemas and metadata from.
* Type: string
* Example:
```json
"schema-registry.url": "http://schema-registry:8081"
```
* Importance: high
#### Configuration prefixes
The remaining configurations represent prefixes that are used to determine configurations for external services used by Streambased
***
```properties
coonfig.source.[name].*
```
A prefix used to pass Kafka connection configurations to Streambased I.S.K. This applies only when `config.provider` is set to `properties` and `[name]` is included in `config.sources`.
* Example:
config.source.source1.bootstrap.servers=kafka1:9092
* Environment Prefix: `ISK_CONFIG_SOURCE_[name]_`
***
```properties
coldset.client.*
```
Additional properties for connecting to an Iceberg provider for coldset data
* Example:
coldset.client.rest.access-key-id=admin
* Environment Prefix: `ISK_CONFIG_SOURCE_[name]_`