private Executor createReadIndexExecutor() {
        final StoreEngineOptions opts = new StoreEngineOptions();
        return StoreEngineHelper.createReadIndexExecutor(opts.getReadIndexCoreThreads());
    }
@author likun (saimu.msm@antfin.com)
jraft-example/src/main/java/com/alipay/sofa/jraft/example/counter/CounterServiceImpl.java