Update retrying client documentation

[iDneprov]

Update retrying client documentation

I haven't forgotten about:

• Tests
• Changelog
• Documentation
• Commit messages comply with the guideline
• Cleanup the code for review. See checklist

Related issues:

Closes #309

[ArtDu]

You can have a more visual example and complex example for it cause it's more complex API:

...
.withProxyMethodMapping(builder -> builder.withDeleteFunctionName("delete_with_error_if_not_found"))
.withRetryingByNumberOfAttempts(5, 
             // You can use default predicates from TarantoolRequestRetryPolicies for checking errors 
             retryNetworkErrors() 
                 // Also you can use your own predicates and combine them with each other 
                 .or(e -> e.getMessage().contains("Unsuccessful attempt")) 
                 // Or with defaults 
                 .or(retryTarantoolNoSuchProcedureErrors())
                 .or(retryDeleteError()), 
             // Also you can set delay in millisecond between attempts 
             factory -> factory.withDelay(300) 
         ) 
...


space(...).delete(); // retrying 
space(...).insert();

[ArtDu]

You dont' have to use Thread API, you can't guarantee that your insert method will be called after deletion. It'd better to use CompletableFuture API, for e.g.

AtomicInteger retryingCounter = new...
...
.or(e -> {
    retryingCounter.addAndGet();
    return e.getMessage().contains("Records not found"); 
})
...
CompletableFuture deleteFuture = retryingClient.space(SPACE_NAME).delete(conditions);
retry(() -> assertEquals(1, retryingCounter.get()))
space.insert(tupleFactory.create(1, null, "FIO", 50, 100)).get();
deleteFuture.get();

But for this you need it in TarantoolUtils.java

public static Integer DEFAULT_RETRYING_ATTEMPTS = 5;
    public static Integer DEFAULT_RETRYING_DELAY = 100;

    public static void retry(Runnable fn) throws InterruptedException {
        retry(DEFAULT_RETRYING_ATTEMPTS, DEFAULT_RETRYING_DELAY, fn);
    }

    public static void retry(Integer attempts, Integer delay, Runnable fn) throws InterruptedException {
        while (attempts > 0) {
            try {
                fn.run();
                return;
            } catch (AssertionError ignored) {
            }

            --attempts;
            Thread.sleep(delay);
        }
        fn.run();
    }

[ArtDu]

I still don't believe that it works from the first attempt, but good for you :)

[akudiyar]

"I use" -> "we use" looks better I believe

[akudiyar]

Or "let's consider a custom delete function"

[iDneprov]

"I use" -> "we use" looks better I believe

I don't think so

[iDneprov]

Or "let's consider a custom delete function"

This looks better. I'll increase the formality of language in documentation soon #356