public void destroy() {
        for (final ConcurrentMap<PeerPair, PeerRequestContext> map : this.peerRequestContexts.values()) {
            for (final PeerRequestContext ctx : map.values()) {
                ctx.destroy();
            }
        }
        this.peerRequestContexts.clear();
    }
The executor selector to select executor for processing request.
jraft-core/src/main/java/com/alipay/sofa/jraft/rpc/impl/core/AppendEntriesRequestProcessor.java