The following is the architecture in our organizations.
We have a distributed system across multiple offices. Where each office works independently on their data (local data - unique id's in database). Sometimes these offices have to share data among themselves.
What is the best way of designing software(architecture) where data can be shared across multiple offices.
Scenario - Lets say an office 'A' is capturing data about a contact (Phillip with id- 258)
where the contact is tied to multiple organizations (located locally) and is involved in multiple events (local events) .
Lets say another office 'B' also is working on Phillips profile.
Whats the best way , where office A and B can share Phillips profile (without creating duplicates and not making it a central system).
Any changes to Phillip will show up in both of these systems (regarding organizations or local events he is related to from either of the office).
Thanks!
I think the answer is to centralize the data base. You could use the cloud, or pick one office that is the main and all other offices update the main.
Next up my choice would be some form of replication at the database level. You would have to review the options provided by your database provider.
You could write a bunch of code, something like Restful services at each office and an update at one office would automatically send the change to the other offices.
Related
How multiple teams(which own different system components/micro-services) in a big tech company share their databases.
I can think of multiple use cases where this would be required. For example in an e-commerce firm, same product will be shared among multiple teams like product at first will be part of product onboarding service, then may be catalog service (which stores all products and categories), then search service, cart service, order placing service, recommendation service, cancellation & return service and so on.
If they don't share any db then
Do they all have redundant copy of the products with same product ID and
Wouldn't there be a challenge to achieve consistency among multiple team.
There are multiple related doubt I have in both the case wether they share DB or not.
I have been through multiple tech blogs and video on software design, and still didn't get satisfying answer. Do share some resources which can give a complete workflow of how things work end-to-end in a big tech firm.
Thank you
In the microservice architecture, each microservice exposes endpoints where other microservice can access shared information between the services. So one service would store as minimal information of a record that is managed by another microservice.
For example if a user service would like to fetch orders for a particular user in an e-commerce case, then the order service would expose an endpoint given a user id would return all orders related to the userid supplied and so on...so essentally the only field related to the user that the order service needs to store is the userid, the rest of the user details is irrelevant to it.
To further improve the cohesion and understanding between teams, data discovery apis/documentation are also built to share metadata of databases to other teams to further explain what each table/field means for one to efficiently plan out a microservice. You can read more about how such companies build data discovery tools
here
If I understand you correctly, you are unsure how different departments receive data in a company?
The idea is that you create reusable and effective API's to solve this problem.
Let's generically say the company we're looking at is walmart. Walmart has millions of items in a database(s). Each item has a unique ID etc etc.
If Walmart is selling items online via walmart.com, they have to have a way to get those items, so they create API's and use them to grab items based on certain query conditions.
Now, let's say walmart has decided to build an app... well they need those exact same items! Well, good thing we already created those API's, we will use the exact same ones to grab the data.
Now, how does Walmart manage which items are available at which store, and at what price? They would usually link this meta data through additional database schema tables and tying them all together with primary and foreign keys.
^^ This essentially allows walmart to grab ONLY the item out of their CORE database that only has details that are necessary to the item (e.g. name, size, color, SKU, details, etc), and link it to another database that is say, YOUR local walmart that contains information relevant to only your walmart location in regard to that item (e.g. price, stock, aisle number etc).
So using multiple databases yes, in a sense.
Perhaps this may drive you down some more roads: https://learnsql.com/blog/why-use-primary-key-foreign-key/
https://towardsdatascience.com/designing-a-relational-database-and-creating-an-entity-relationship-diagram-89c1c19320b2
There's a substantial diversity of approaches used between and even within big tech companies, driven by different company/org cultures and different requirements around consistency and availability.
Any time you have an explicit "query another service/another DB" dependency, you have a coupling which tends to turn a problem in one service into a problem in both services (and this isn't a necessarily a one-way thing: it's quite possible for the querying service to encounter a problem which cascades into a problem in the queried service (this is especially possible when a cache becomes load-bearing, which has led to major outages at at least one FANMAG in the not-that-distant past)).
This has led some companies that could be fairly called big tech to eschew that approach in their service design, typically by having services publish events describing what has changed to a durable log (append-only storage). Other services subscribe to that log and use the events to construct their own eventually consistent view of the data owned by the other service (i.e. there's some level of data duplication, with services storing exactly the data they need to function).
Imagine a large corp with dozens of companies, each with their own website and each website will have their own unique functional requirements
Most data on each website will be specific to that website
Each website can edit its own data
Some data will be shared across all websites
There will be a central CMS that is allowed to edit this data, but other websites can read and use that data
e.g. say you're planning the infrastructure for a company that owns multiple sub-companies that make different kinds of products, some in the same category (cereal, food), others in completely different categories (books, instruments). Some are marketing websites, some are for CRM, some are online stores
there are a list of regulatory requirements that affect all products
each company should manage the status of compliance of its own products to each requirement
when a new requirement surfaces, details regarding that requirement should only be entered once
How would the multiple databases be coordinated?
edit: added more info per Bob's suggestions
Thanks for the incredibly insightful questions!
compliance data is not shared, silo'd within each site
shared data is only on the one enterprise-wide database, they will mostly be "types of [thing]"
no conclusive list of instances where they'll be used but currently it'd be to populate CMS dropdowns for individual sites.
changes to shared data would occur a few times a year.
Ideally changes would be reflected within a few minutes, but an hour or so should be acceptable
very low volume in shared data.
All DBs will be new, decision on which DB is pending current investigation.
Sub-systems will expose REST api
Here are some ways I have seen this handled, you need to think about the implications of each structure based on the details of your particular business domain. All can work, but all have to be carefully set up if they are going to work.
One database for shared information and one for each client for client-specific information. Set up the overall application so that the first thing you put in the application on log in is the client and it connects to the correct client. People might have to also have a way to change the client if users will handled multiples.
Separate servers for each client if they completely need to be siloed. Database changes are by script (and in source control) and are applied to each server as need be. So the changes to the central database might have a job that runs to push any data changes to the other servers
All the data in one database, but making sure each table has a client_id so that the data is always filtered correctly by client. You can set up separate views by client, so that the users can only see the clients they are supposed to see. This only works if the data for each client is substantially in the same form.
And since you are in a regulatory environment, I strongly urge that you create an audit database that is updated by database triggers (never audit from the application, you will lose changes to the data) for each database.
I agree with Chris that, even after both the sets of questions, there is still a big set of possible solutions. For instance, if the databases were the same technology, and the shared data were stored in the same way in each one, you could do db-level replication from the central db to the others. Is it OK to have 2 separate dbs per application (one with shared stuff and one with not-shared?) - this would influence the kind of replication.
Or you could have a purely code solution, where clicking publish in a GUI that updates the central db calls a set of APIs that also update the other dbs. Or micro-services - updating the central db also creates a message on a shared queue, that is picked up by services that each look after a different db and apply the updates in whatever form makes sense for that db.
It depends on (among the things already mentioned) what your organisation's technology strategy is, what technology and skills you already have in-house, and so on.
So this is as much an architecture question as it is a db question.
I don't think this question is sufficiently clear to get a single answer. However there are a few possibilities.
In many cases, where you have shared data you want to have a single point of ownership of that information. It could be in a database, in an excel file (which can then be turned into csv and periodically loaded on all dbs), or some other form. The specifics depend on what is shared exactly.
Now in this case it sounds like you are going to have some sort of legal department in charge of some shared information and they will manage that data, which will then be shared to the other sites. This might be done with an application they manage which aggregates information from the other companies or it could be data which is pushed to their systems.
A final point:
Software is at its best when it facilitates human solutions to human problems, not when it tries to solve those problems directly. In these cases, you probably want a good human solution in place and then to look at what software can do to support that. A lot of the issues (who owns the information?) will already have been solved and you will be simply automating what is already done.
We are creating a web solution that contains large number of users, their events, calendars and content to be managed. This solution can be white-labeled and can be sold to other vendors as a services, i.e. Though the hosting is in our SINGLE server but thy will have their own administrator and there own users and separate contents, that are completely disconnected to the other vendors. For example we are going to host the solution as
www.example.com/company1
www.example.com/company2
www.example.com/company3
The question is should we use different database for different company, or we should use single database for managing all the company.
Thanks
You should use separate databases for each company, unless you are offering some sort of service where the companies know that data is being pooled.
This is a question of data protection. No matter how much you swear that one company can only see their data in the table, you may not be able to convince prospective clients of this fact.
In addition, you need to keep the options open of running the databases on different servers. You don't want peak performance at one company to affect another company. Or, you don't want a special change for one company -- which might require bringing down the application with their knowledge -- to affect other clients.
Here's my problem. I built a web app, and naturally kept the data in a database which describes that app's domain. Afterwords, I built another web app for the same organization, and used a seperate database to describe that app's domain and store data... and naturally a couple more projects came up and for each app I've isolated it's data to a single database. Deveolpment wise, I think it's ok, as I can maintain changes to the data structure and data at the app's database.
Considering these apps belong to the same organization, there tends to be plenty of data replicated between them, like department names, job titles, shop names, etc. Most of these tables hold the same data, but are not exactly the same in each database, and are not always used by all of the apps. Changes to this data, though, needs to be changed at all the apps (sometimes in a diferent ways) creating a growing management "hassle".
So I've been think of a way to get some syncronization between the data. I want an easier management - update at one app (or a central app) and update all the databases as needed by each app - and also a better way to share data between apps (like maybe mash up data from differnt apps in a new app to alow specific analysis). Most of the data I'm refering to is used as contraints more than being core domain concept, describing the organization rather than describing a particular domain.
I'm looking for opinions on some ways to get this done.
My first idea was to grab comun data structures, like the department names' table i mentioned, and stick'em in a core database. Any updates to the data would be done at this database, through a dedicated web app, and I'd apply some sort of Observer or Publisher / Suscriber Pattern for these changes - on changes the app would notify observing apps (through there dedicated webservice) that the changes occured and allow for the app to grab the new data and use it as it needs. GUIDs could be user as a reference to identify the same data throughout the apps. Also, I could build web services for read and search operations that don't need to be in a specific app's database, but could be useful to it.
A second idea would be that each app manage it's own data, and the apps could observe one another. A change in one could notify others that share the same data structure that the change occurred. I could still use some GUIDs and even build services on any of the apps. I think this would also be less excessive in terms of duplication of data, but might be harder to manage as each app would eventually be coupled to other apps, and I would some how have to distribute responsabilities as to which app controls what information.
I'm really curious as to something of this genre of data distibuition and syncing would work and even be recomended. Opions and other ideas are more than welcome!
What you describe here is a typical case for a "Master Data Management" system. EAI vendors (Oracle, TIBCO, IBM) offer such products. They resemble your first solution, being centralised databases with synchronization processes, detecting changes in external data sources, grabbing the changes and synchronizing data out to other external databases. They also provide a user interface to change master data directly.
MDM software are expensive, but you can implement a custom solution which will be - at least initially - cheaper than purchasing one. Both of your solutions make technical sense but there is a difference in their manageability.
The first one is better, if you can dedicate a responsible person/organization to take care of it and the business owners of your services can agree on making changes via this new centralised system.
The second solution shares the responsibility between the service owners. The hard task here is to identify the owner of each type of information (business object).
I cannot advise a solution without a deeper knowledge of your systems and organizations, but I hope I could give some ideas.
If I am building a CRM web application to sell as a membership service, what is the best method to design and deploy the database?
Do I have 1 database that houses 100s of records per table or deploy multiple databases for different clients?
Is it really an issue to use a single database since I believe sites like Flickr use them?
Multiple clients is called "multi-tenant". See for example this article "Multi-Tenant Data Architecture" from Microsoft.
In a situation like a CRM system, you will probably need to have separate instances of your database for each customer.
I say this because if you'd like larger clients, most companies have security policies in place regarding customer data. If you store their customer data in the same database as another customer, you're running the risk of exposing one companies confidential data to another company (a competitor, etc.).
Sites like Flickr don't have to worry about this as much since the majority of us out on the Interwebs don't have such strict policies regarding our personal data.
Long term it is easiest to maintain one database with multiple clients' data in it. Think about deployment, backup, etc. However, this doesn't keep you from having several instances of this database, each containing a subset of the full client dataset. I'd recommend to grow the number of databases after you have established the usefulness/desirability of your product. Having complex infrastructure is not necessary if you have no traffic....
So, I'd just put a client id in the relevant tables and smile when client 4 comes in and the extent of your new deployment is one insert statement.