Javanica: Dynamic thread pool key, based on parameters

[jochenchrist]

With hystrix-javanica, is there a way to define the hystrix thread pool dynamically, based on the Hystrix Command parameters?

To clarify:
In the example below, I'd like to use a different thread pool for each different bank value.

Example:

    @HystrixCommand(fallbackMethod = "getBalanceFromCache")
    public AccountBalance getBalance(Bank bank, String iban) {
        final String bankUrl = environment.getProperty("bank." + bank.name().toLowerCase());
        final URI uri = UriComponentsBuilder.fromHttpUrl(bankUrl).buildAndExpand(iban).toUri();
        return restTemplate.getForObject(uri, AccountBalance.class);
    }

    public AccountBalance getBalanceFromCache(Bank bank, String iban) {
        logger.info("GET Fallback for Bank {}", bank);
        return AccountBalanceCache.getCachedAccountBalance(bank, iban);
    }

A possible approach would be to define a threadPoolKeyMethod with the same parameters as the hystrix command, similar to the fallbackMethod, which provides a key to use.

    @HystrixCommand(fallbackMethod = "getBalanceFromCache", threadPoolKeyMethod = "threadPoolKey")
    public AccountBalance getBalance(Bank bank, String iban) {
        final String bankUrl = environment.getProperty("bank." + bank.name().toLowerCase());
        final URI uri = UriComponentsBuilder.fromHttpUrl(bankUrl).buildAndExpand(iban).toUri();
        return restTemplate.getForObject(uri, AccountBalance.class);
    }

    public HystrixThreadPoolKey threadPoolKey(Bank bank, String iban) {
        return HystrixThreadPoolKey.Factory.asKey("getBalance_" + bank);
    }

Ideas?

[dmgcodevil]

No, there is no such ability. If I got you correctly you need to generate thread pools in runtime with keys based on command parameters, but I my opinion it can lead to many thread pool instances, did you think about that ? Curious, why you need that ability, as variant you can create different methods, annotate them using @HystrixCommand annotation and invoke certain method based on parameters of root method. For example:

public AccountBalance getBalance(Bank bank, String iban) {
          if (bank.getName() == "Great Trust Bank") {
                return getGTBankBalance(bank, iban);
           }
    }

@HystrixCommand(threadPoolKey = "YourSpecificThreadPoolKey")
public AccountBalance getGTBankBalance(Bank bank, String iban) {
           ....
    }

But I'm not sure that this will work within same class i.e. if 'getBalance' and 'getGTBankBalance' defined in the same class
Could you check will this approach work for you ? If not then I'll implement this feature.

[mattrjacobs]

Closing due to inactivity. If there is still interest in this, please reopen

[anjia0532]

@jochenchrist my gist https://gist.github.com/anjia0532/e30bba219a169927160ba336d1b7aec0