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Are there any limitations around the number of open Ably connections?
Customers should reuse the same Ably Realtime instance (which is representation of represents a single connection to Ably) to subscribe on multiple channels. We couldn't identify any reasons to create multiple connections other than the hard limit of inbound messages per connection which is 100 messages per second and the hard limit of 200 channels per connection. If your subscription fits into these limitations, you do not need to deal with the complexity of managing multiple Ably Realtime instances but can only use a single connection. Currently an Ably token which is issued by Genius APIs, only allows subscribing to a single channel and thus consuming data for a single fixture. Looking forward, this limitation would be mitigated by issuing tokens that allow access to multiple channels but until then, there is no customer specific limit for the number of connections that can be established. There is a hard limit of inbound messages per connection which is 100 messages per second.
Are there any limitations around the number of channel subscriptions per connection?
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We do not recommend subscribing to a channel too much before fixture start time. We suggest 3 hours before the kickoff should be a sensible interval of time to create your subscription. In case you start creating subscriptions for games that will start in a few days, you will start hitting the limits for maximum channels per connection. Creating a subscription to channel with no publisher will not result in an error. Please keep in mind that each Ably access token has expiration time and needs to be refreshed so if you create a subscription too early, you will have to refresh the token multiple times.