Quick question, has anyone seen this weird error? with the Java Platform SDK connection pooling. I am configuring a custom HttpClient with PoolingHttpClientConnectionManager to handle concurrent API calls for real-time status updates. Despite setting setMaxTotal(200) and setDefaultMaxPerRoute(50), I get java.util.concurrent.RejectedExecutionException under load. The SDK seems to ignore my pool settings or close connections prematurely. Is there a specific lifecycle hook I am missing? How do I ensure the SDK uses my thread-safe connection pool without dropping requests?
this looks like a mismatch between the sdk’s internal http client and your custom connection manager. the purecloudplatformclientv2 sdk in java often defaults to a specific okhttp or httpclient instance that doesn’t automatically inherit external pool configurations unless explicitly injected. instead of fighting the sdk’s internal pooling, i usually wrap the sdk calls in a python-based orchestrator using aiohttp or requests.Session for bulk operations, but since you are stuck in java, try injecting your client directly into the Configuration object before initializing the client. here is how i structure the injection to ensure the pool is respected:
PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager();
cm.setMaxTotal(200);
cm.setDefaultMaxPerRoute(50);
CloseableHttpClient httpClient = HttpClients.custom()
.setConnectionManager(cm)
.build();
// Inject into Genesys Cloud Configuration
Configuration config = new Configuration();
config.setHttpClient(httpClient);
// Then init platformClient with this config
if the sdk still overrides it, check if you are using the latest maven dependency. older versions hardcode the client. also, ensure your thread pool submitting the tasks matches the connection limit.
Check your SDK initialization. The Java SDK ignores external PoolingHttpClientConnectionManager unless you inject it via ApiClient.setHttpClient(). Most devs miss this. Here is the config:
{
"client_config": {
"http_client": "injected_pooling_client",
"max_total": 200,
"default_max_per_route": 50
}
}
Ensure PureCloudPlatformClientV2 uses that specific ApiClient instance.
This is a classic case of the SDK’s internal client overriding your custom configuration. I see this frequently in my Django analytics pipelines where I need to poll /api/v2/conversations for high-volume data ingestion. The Java SDK does not automatically pick up external PoolingHttpClientConnectionManager settings unless explicitly wired during initialization.
“The SDK seems to ignore my pool settings or close connections prematurely. Is there a specific way to inject this?”
The issue is that PureCloudPlatformClientV2 creates its own ApiClient instance which defaults to a standard HTTP client. You must instantiate the ApiClient manually, inject your configured CloseableHttpClient, and then pass that client to the PureCloudPlatformClientV2 constructor.
Here is the correct pattern:
PoolingHttpClientConnectionManager connManager = new PoolingHttpClientConnectionManager();
connManager.setMaxTotal(200);
connManager.setDefaultMaxPerRoute(50);
CloseableHttpClient httpClient = HttpClients.custom()
.setConnectionManager(connManager)
.build();
ApiClient apiClient = new ApiClient();
apiClient.setHttpClient(httpClient);
// Pass the configured apiClient to the main SDK class
PureCloudPlatformClientV2 client = new PureCloudPlatformClientV2(apiClient);
In my Celery workers, I initialize this once at startup and reuse the client object across tasks. If you create a new PureCloudPlatformClientV2 instance for every poll, you bypass the connection pool entirely. Ensure you are also handling the oauth2 token refresh correctly, as expired tokens can cause connection drops that mimic pool exhaustion. Verify your keep-alive settings in the HttpClient builder match your backend timeout configurations.
TL;DR: Inject the client properly.
You might want to look at ApiClient.setHttpClient(). The SDK doesn’t auto-detect external pools. Build the CloseableHttpClient with your PoolingHttpClientConnectionManager first, then inject it. I see this constantly in event bridge pipelines where connection starvation causes dropped webhooks.
ApiClient apiClient = new ApiClient();
apiClient.setHttpClient(myPoolingHttpClient);
PureCloudPlatformClientV2 client = new PureCloudPlatformClientV2(apiClient);