data-scientists/ocean.py/ocean-compute-tech-details.md
---
description: Technical details about OceanCompute functions
---
# Ocean Compute Tech Details
Using this class, we are able to manipulate a compute job, run it on Ocean environment and retrieve the results after the execution is finished.
### Start Compute Job
* **start**(`self`, `consumer_wallet`, `dataset: ComputeInput`, `compute_environment: str`, `algorithm: Optional[ComputeInput] = None`, `algorithm_meta: Optional[AlgorithmMetadata] = None`, `algorithm_algocustomdata: Optional[dict] = None`, `additional_datasets: List[ComputeInput] = []`) -> `str`
Starts a compute job.
It can be called within Ocean Compute class.
**Parameters**
* `consumer_wallet` - the `eth Account` of consumer who pays & starts for compute job.
* `dataset` - `ComputeInput` object, each of them includes mandatory the DDO and service.
* `compute_environment` - `string` that represents the ID from the chosen C2D environment.
* `additional_datasets` - list of `ComputeInput` objects for additional datasets in case of starting a compute job for multiple datasets.
**Optional parameters**
* `algorithm` - `ComputeInput` object, each of them includes mandatory the DDO and service for algorithm.
* `algorithm_meta` - either provide just the algorithm metadata as `AlgorithmMetadata.`
* `algorithm_algocustomedata` - additional user data for the algorithm as dictionary.
**Returns**
`str`
Returns a string type job ID.
**Defined in**
[ocean/ocean_compute.py](https://github.com/oceanprotocol/ocean.py/blob/main/ocean_lib/ocean/ocean_compute.py#LL32C4-L70C33)
<details>
<summary>Source code</summary>
```python
@enforce_types
def start(
self,
consumer_wallet,
dataset: ComputeInput,
compute_environment: str,
algorithm: Optional[ComputeInput] = None,
algorithm_meta: Optional[AlgorithmMetadata] = None,
algorithm_algocustomdata: Optional[dict] = None,
additional_datasets: List[ComputeInput] = [],
) -> str:
metadata_cache_uri = self._config_dict.get("METADATA_CACHE_URI")
ddo = Aquarius.get_instance(metadata_cache_uri).get_ddo(dataset.did)
service = ddo.get_service_by_id(dataset.service_id)
assert (
ServiceTypes.CLOUD_COMPUTE == service.type
), "service at serviceId is not of type compute service."
consumable_result = is_consumable(
ddo,
service,
{"type": "address", "value": consumer_wallet.address},
with_connectivity_check=True,
)
if consumable_result != ConsumableCodes.OK:
raise AssetNotConsumable(consumable_result)
# Start compute job
job_info = self._data_provider.start_compute_job(
dataset_compute_service=service,
consumer=consumer_wallet,
dataset=dataset,
compute_environment=compute_environment,
algorithm=algorithm,
algorithm_meta=algorithm_meta,
algorithm_custom_data=algorithm_algocustomdata,
input_datasets=additional_datasets,
)
return job_info["jobId"]
```
</details>
### Compute Job Status
* **status**(`self`, `ddo: DDO`, `service: Service`, `job_id: str`, `wallet`) -> `Dict[str, Any]`
Gets status of the compute job.
It can be called within Ocean Compute class.
**Parameters**
* `ddo` - DDO offering the compute service of this job
* `service` - Service object of compute
* `job_id` - ID of the compute job
* `wallet` - eth Account which initiated the compute job
**Returns**
`Dict[str, Any]`
A dictionary which contains the status for an existing compute job, keys are `(ok, status, statusText)`.
**Defined in**
[ocean/ocean_compute.py](https://github.com/oceanprotocol/ocean.py/blob/main/ocean_lib/ocean/ocean_compute.py#LL72C5-L88C24)
<details>
<summary>Source code</summary>
{% code overflow="wrap" %}
```python
@enforce_types
def status(self, ddo: DDO, service: Service, job_id: str, wallet) -> Dict[str, Any]:
"""
Gets job status.
:param ddo: DDO offering the compute service of this job
:param service: compute service of this job
:param job_id: str id of the compute job
:param wallet: Wallet instance
:return: dict the status for an existing compute job, keys are (ok, status, statusText)
"""
job_info = self._data_provider.compute_job_status(
ddo.did, job_id, service, wallet
)
job_info.update({"ok": job_info.get("status") not in (31, 32, None)})
return job_info
```
{% endcode %}
</details>
### Compute Job Result
* **result**(`self`, `ddo: DDO`, `service: Service`, `job_id: str`, `index: int`, `wallet` ) -> `Dict[str, Any]`
Gets compute job result.
It can be called within Ocean Compute class.
**Parameters**
* `ddo` - DDO offering the compute service of this job
* `service` - Service object of compute
* `job_id` - ID of the compute job
* `index` - compute result index
* `wallet` - eth Account which initiated the compute job
**Returns**
`Dict[str, Any]`
A dictionary wich contains the results/logs urls for an existing compute job, keys are `(did, urls, logs)`.
**Defined in**
[ocean/ocean_compute.py](https://github.com/oceanprotocol/ocean.py/blob/main/ocean_lib/ocean/ocean_compute.py#LL90C5-L106C22)
<details>
<summary>Source code</summary>
{% code overflow="wrap" %}
```python
@enforce_types
def result(
self, ddo: DDO, service: Service, job_id: str, index: int, wallet
) -> Dict[str, Any]:
"""
Gets job result.
:param ddo: DDO offering the compute service of this job
:param service: compute service of this job
:param job_id: str id of the compute job
:param index: compute result index
:param wallet: Wallet instance
:return: dict the results/logs urls for an existing compute job, keys are (did, urls, logs)
"""
result = self._data_provider.compute_job_result(job_id, index, service, wallet)
return result
```
{% endcode %}
</details>
### Compute Job Result Logs
* **compute\_job\_result\_logs**(`self`, `ddo: DDO`, `service: Service`, `job_id: str`, `wallet`, `log_type="output"`) -> `Dict[str, Any]`
Gets job output if exists.
It can be called within Ocean Compute class.
**Parameters**
* `ddo` - DDO offering the compute service of this job
* `service` - Service object of compute
* `job_id` - ID of the compute job
* `wallet` - eth Account which initiated the compute job
* `log_type` - string which selects what kind of logs to display. Default "output"
**Returns**
`Dict[str, Any]`
A dictionary which includes the results/logs urls for an existing compute job, keys are `(did, urls, logs)`.
**Defined in**
[ocean/ocean_compute.py](https://github.com/oceanprotocol/ocean.py/blob/main/ocean_lib/ocean/ocean_compute.py#LL108C5-L130C22)
<details>
<summary>Source code</summary>
{% code overflow="wrap" %}
```python
@enforce_types
def compute_job_result_logs(
self,
ddo: DDO,
service: Service,
job_id: str,
wallet,
log_type="output",
) -> Dict[str, Any]:
"""
Gets job output if exists.
:param ddo: DDO offering the compute service of this job
:param service: compute service of this job
:param job_id: str id of the compute job
:param wallet: Wallet instance
:return: dict the results/logs urls for an existing compute job, keys are (did, urls, logs)
"""
result = self._data_provider.compute_job_result_logs(
ddo, job_id, service, wallet, log_type
)
return result
```
{% endcode %}
</details>
### Stop Compute Job
* **stop**(`self`, `ddo: DDO`, `service: Service`, `job_id: str`, `wallet`) -> `Dict[str, Any]`
Attempts to stop the running compute job.
It can be called within Ocean Compute class.
**Parameters**
* `ddo` - DDO offering the compute service of this job
* `service` - Service object of compute
* `job_id` - ID of the compute job
* `wallet` - eth Account which initiated the compute job
**Returns**
`Dict[str, Any]`
A dictionary which contains the status for the stopped compute job, keys are `(ok, status, statusText)`.
**Defined in**
[ocean/ocean_compute.py](https://github.com/oceanprotocol/ocean.py/blob/main/ocean_lib/ocean/ocean_compute.py#LL132C5-L146C24)
<details>
<summary>Source code</summary>
{% code overflow="wrap" %}
```python
@enforce_types
def stop(self, ddo: DDO, service: Service, job_id: str, wallet) -> Dict[str, Any]:
"""
Attempt to stop the running compute job.
:param ddo: DDO offering the compute service of this job
:param job_id: str id of the compute job
:param wallet: Wallet instance
:return: dict the status for the stopped compute job, keys are (ok, status, statusText)
"""
job_info = self._data_provider.stop_compute_job(
ddo.did, job_id, service, wallet
)
job_info.update({"ok": job_info.get("status") not in (31, 32, None)})
return job_info
```
{% endcode %}
</details>
### Get Priced C2D Environments
* **get\_c2d\_environments**(`self`, `service_endpoint: str`, `chain_id: int`)
Get list of compute environments.
It can be called within Ocean Compute class.
**Parameters**
* `service_endpoint` - string Provider URL that is stored in compute service.
* `chain_id` - using Provider multichain, `chain_id` is required to specify the network for your environment. It has `int` type.
**Returns**
`list`
A list of objects containing information about each compute environment. For each compute environment, these are the following keys: `(id, feeToken, priceMin, consumerAddress, lastSeen, namespace, status)`.
**Defined in**
[ocean/ocean_compute.py](https://github.com/oceanprotocol/ocean.py/blob/main/ocean_lib/ocean/ocean_compute.py#LL148C4-L150C84)
<details>
<summary>Source code</summary>
{% code overflow="wrap" %}
```python
@enforce_types
def get_c2d_environments(self, service_endpoint: str, chain_id: int):
return DataServiceProvider.get_c2d_environments(service_endpoint, chain_id)
```
{% endcode %}
</details>
### Get Free C2D Environments
* **get\_free\_c2d\_environment**(`self`, `service_endpoint: str`, `chain_id`)
Get list of free compute environments.
Important thing is that not all Providers contain free environments (`priceMin = 0`).
It can be called within Ocean Compute class.
**Parameters**
* `service_endpoint` - string Provider URL that is stored in compute service.
* `chain_id` - using Provider multichain, `chain_id` is required to specify the network for your environment. It has `int` type.
**Returns**
`list`
A list of objects containing information about each compute environment. For each compute environment, these are the following keys: `(id, feeToken, priceMin, consumerAddress, lastSeen, namespace, status)`.
**Defined in**
[ocean/ocean_compute.py](https://github.com/oceanprotocol/ocean.py/blob/main/ocean_lib/ocean/ocean_compute.py#LL152C5-L155C87)
<details>
<summary>Source code</summary>
{% code overflow="wrap" %}
```python
@enforce_types
def get_free_c2d_environment(self, service_endpoint: str, chain_id):
environments = self.get_c2d_environments(service_endpoint, chain_id)
return next(env for env in environments if float(env["priceMin"]) == float(0))
```
{% endcode %}
</details>