Spanner: RESOURCE_EXHAUSTED No session available in the pool.

[lascarayf]

I am using the Spanner client library for Java and i configure the client using Spring (Java 10 and Docker)

After a while, the application start to log the following message but i don't understand why. The application concurrency is minimal. It's seem the sessions aren't reused.

I monitor the session with Stackdriver and they are below 20.

If i remove setFailIfPoolExhausted the applicacion hang instead of throwing exception RESOURCE_EXHAUSTED.

RESOURCE_EXHAUSTED: No session available in the pool. Maximum number of sessions in the pool can be overridden by invoking SessionPoolOptions#Builder#setMaxSessions. Client can be made to block rather than fail by setting SessionPoolOptions#Builder#setBlockIfPoolExhausted.

@Configuration
public class SpannerConfig {

 @Value("${datasource.instanceId}")
 private String instance;

 @Value("${datasource.databaseId}")
 private String database;

 @Bean
 public Spanner spannerService() throws IOException {

 SessionPoolOptions sessionPoolOptions = SessionPoolOptions.newBuilder()
 .setFailIfPoolExhausted()
 .setMinSessions(5)
 .setMaxSessions(100)
 .build();

 SpannerOptions options = SpannerOptions.newBuilder()
 .setSessionPoolOption(sessionPoolOptions)
 .build();

 return options.getService();
 }


 @Bean
 public DatabaseClient spannerClient(Spanner spannerService) {
 DatabaseId databaseId = DatabaseId.of(spannerService.getOptions().getProjectId(), instance, database);
 return spannerService.getDatabaseClient(databaseId);
 }
}

[lascarayf]

i add the stackoverflow link
https://stackoverflow.com/questions/52695111/resource-exhausted-no-session-available-in-the-pool

[avaisberg]

I have the same error. I dont known why.

News?

Thanks!

[snehashah16]

this has been answered on Stack Overflow

short answer:
Try putting this in a try-with-resources block:
try (ResultSet rs = spannerClient.singleUse().executeQuery(statement)) { ... }