Events loading too slow

Question

I have a dapp running on rinkeby at the moment, you can try it now on cryptogol.io, but I am facing a problem when reading events from the Blockchain. For example, yesterday I make the events happens, so everyone can interact with the site. Here is the code for listening to the event (it is being ran every time someone opens the page at www.cryptogol.io/market.html:

listenForEvents: function() {
  console.log("escuchando")
    App.contracts.KickerADN.deployed().then(function(instance) {
        instance.AdnCreated({}, {
            fromBlock: 0,
            toBlock: 'latest'
        }).watch(function(error, event) {
            App.loadBody(event.args._adn.toNumber());
        });
    });
}

When you open the page it can take more than 1 minute to load the event. The function is being called normally but the event is not getting it on time. Any idea?

Answer 1

The event of the tnx call only fired when the tnx was confirmed a.k.a when tnx was including in a sealed block so it takes time.

Answer 2

How about change design? It is loading all blocks. AdnCreated is event accessor and the 1st arg is search condition for indexed event. It will reduce scanning target count. 2nd arg is skipper. fromBlock allows you to skip some block. And so if you design your contract to ignorable obsoleted state, checkpointing would make your log feching faster. And putting cache server is also one choice. Some of users would say it's centralized entity though, actually that server isn't killing fund safety.