In a flutter app stream are used. If some changes happens in firestore database then It'll be reflected in the app too. Can we do the same with the MySQL database as a backend server for storing data. Will the changes in MySQL reflected in the flutter app too?
MySQL does not have built-in realtime capabilities like Firestore. Firestore is fairly unique in this way. Typically, with SQL type databases, you have to repeat the query ("polling the database") to find any updates. There might be other middleware products you can use to simulate realtime updates, but you would have to search for and evaluate those for yourself.
Related
In my project, I am storing a lot of data in MySQL automatically. I want, however, the same things to sync with Node.js application's own data storage. What would be the fastest and easiest way to do this when storing data in both storages simultaneously isn't possible?
So, for example, I am storing variable "balance" in MySQL inside one Node.js application. I would want this same balance updated into other Node.js application's own storage but my current Node.js app is not connected to socket or other kind of data transporting mechanism. So how could I fetch data from MySQL in that other Node.js application?
sound look like your project structure is saga pattern.
in your question about update data is can use Kafka to create a topic and 2 node application consume message on same topic to update data into own database.
Currently I am using MySQL as a main database which is not real time database. To synchronize client side data with server and keep data when offline I am considering to add real time database as a slave database in my architecture. Synchronizing data is not easy, so I want to use cloud firestore.
What I searched until now, It seems there is no pratical way to synchronize between not real time RDMS(in my case is MySQL) and cloud firestore. I can not migrate current data to cloud firestore because other services depend on that.
If there is no pratical solution for this, please suggest me the best way. Thanks.
Not sure, but it seems there is no solution to synchronize that. To synchronize such this case, on the client side has to be implemented manually.
I have been thinking about this as well. What I have thought up so far is this.
Use Firestore to create a document.
Write cloud function to listen to create events on the collection that stores that document.
send the created document over http to a rest endpoint that stores that data on a relational db (mysql, postgres), if server is down or status code is anything other than 200, assign true to a boolean flag on the document called syncFailed.
write a worker that periodically fetches documents where syncFailed is true and sends this document to the endpoint again until sync is a success.
THINGS TO CONSIDER
Be careful in adopting this approach with update events. You may accidently create an infinite loop that will cost you all your wealth. If you do add a update listener on a document, make sure you devise a way to avoid creating an infinite loop. You may update a document from an update-listening cloud function that in turn re-triggers this cloud function which in turn updates the document which in turn re-re-triggers this cloud function and so on. Make sure you use a boolean flag on the document or some field as a sentinel value to get out of such a looping situation.
I am creating a messaging app. I have my users stored in a mysql database and messages stored in google datastore a nosql database. However I was wondering what would be the drawbacks of having my messages in a mysql database since I am fetching the message and the user simultaneously.
Is there performance drawbacks?
Generally, different database usage cannot affect anything if your backend architecture is well-defined. Database stores only data to manipulate. I think for authentication you use mySQL and store data in Google Datastore. Performance drawbacks are coming from the bandwidth of your server.
I propose that you must use the same database to store all data, it will be more stable and easy to manage.
What is the best strategy to synchronize the local database with the server one?
The idea is to use a 100% HTML5 application, so every morning, the server database will be duplicated to clients, so the clients will only work on IndexedDB, untill the end of the day, where the clients will send all the data to the server, and then the server will gather them and save them again, but as you can see, it is a lot of work, so is there a better way the IndexedDB or MongoDB offer to connect to each other?
If all your logics are in client, you don't need MongoDB. Just key-value store with REST API and collection query by last-modified is good enough.
I had a sample sync app with Google cloud storage.
I am creating a WP8 App.
I have a created a sqlite database in the isolated storage.
Now my data keeps updating and I want to regularly download the latest data from the server database and update the local database.
The database in the WP8 cannot be changed at the client side so there will be only 1 side data merging.
Which is the best way and service to use?
If you do not work with a large database, you might prefer to replace the device database and not worry about merging. This can be as simple as making an export of the server database, transferring it to the device and then importing it into the device database. The appropriate method of dumping the database on the server side is dependent on the type of database (e.g. mysqldump in the case of MySQL).
If you do work with a large database, or if you are struggling with bandwidth issues on the device, you might want to use a technique to detect differences. One of the easiest methods is change tracking on the database. All modifications can then be logged with an change_at timestamp. The device can then remember which is the last modification it contains, get the new entries, and replicate the changes locally (For in-depth detailed explanation, please provide more information of the server environment and data structure).