Evernote sync speed quadrupled

Synchronizing your notes on all used computers and phones was the key functionality of Evernote from the very beginning of the service in the summer of 2008, initially. Ensuring reliable and stable synchronization is our primary concern. From the side it is not visible, and the best praise for us was just that it just works. From today, it just works faster.

Difficulties with synchronization were due to five indicators:

• the number of notes in your account
• average content size (images, PDF documents, other files),
• the number of users simultaneously synchronizing on one server
• the number of devices you use,
• the volume of collaboration of other users with your notes and notebooks.

All these indicators have increased significantly in recent years.
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When we created the initial service architecture, we dealt with the support of several thousand users, mostly working from one device and creating notes for themselves. We now have tens of millions of users with multiple devices that store and share notes, photos, and documents.

Our infrastructure has grown from a dozen servers to more than seven hundred in several data centers. The original architecture coped well with this growth, but we knew that it could not last forever.

Seven months ago, we started a fundamental reworking of server-based synchronization mechanisms to ensure its reliable operation in the coming decades. In doing so, we have established four key requirements for this task.

1. There should be no noticeable failures in the service, and all data should be saved.
2. Data transfer should be completely invisible to users, so that Evernote itself and other applications integrated with us can use the new synchronization mechanism without a mandatory update.
3. After the start of the new system, we should get a significant performance boost.
4. We must ensure fast and reliable operation over several years, with the possibility of a sharp increase in the use of mobile devices, wearable devices (such as watches or glasses), the appearance of images and larger videos, as well as an increase in the volume of collaboration in the service.

Over the past year, our team has completely reworked the principle of synchronizing notes in Evernote. Then we moved every note, attachment, and every bit of service data to the new sync platform. At the same time, we updated the components on some tired servers. Then we tested the work of the new system. And once again tested. And several times tested.

And finally, we pressed the power button.

Rather, not for everything at once. Some of the servers have already worked with the new synchronization mechanism for several weeks, while others have switched between the old and the new platform to make sure that in both cases, there are no errors on the application side when processing operations, and everything happens identically.

Currently, all Evernote servers are working with a new synchronization mechanism. And it pleases.

results

Synchronization is now 4 times faster than before. This refers to any version of Evernote that you use. Now synchronization often takes just a couple of seconds, and if you have a new computer or phone, then loading notes takes much less time.

If you have a very large account, you have been using Evernote for many years, share notes with other users, or your entire company works with Evernote Business - you will appreciate these improvements.

This is just the beginning.

This is the first stage in our work on synchronization. All of the improvements implemented relate to changes on the server side and do not require any improvements in Evernote applications. In the future, we will update all the applications so that they can get additional benefits from the new service architecture. This will make synchronization even faster. We will also update our API and developer guides so that our partners can also speed up synchronization in their applications.

The main theme of 2014 for us is improving the basic capabilities of Evernote. We are very pleased with the transition to a new infrastructure, to hold it without service downtime was a serious task for our team. As a result, Evernote has become not only more responsive in work, but also prepared for important updates that you will see this year.