This article only applies to websites hosted on our Linux Shared Hosting subscriptions accessed via https://cp.blacknight.com (the Blacknight Control Panel).
The "Resource Limit Is Reached" message (or 508 Status Code) will show when the concurrent connection limit has been reached; this limit is also known as the vhost limit.
You may see that error when visiting the website and also in your error logs as:
Rejecting vhost={your domain name here}
Covered Items
- What Can I Do To Fix This Issue?
- The Limits On Webspaces, On Our Shared Hosting Subscriptions
- How Many Visitors Can Be On My Website At Any One Time?
- What Are The Connections For?
- What Are Webspaces? Is That Not Just My Website?
- I Have Done That, I am Still Getting The "Resource Limit Is Reached" Message?
- A Note On Video/Steaming Media On Your Website
What Can I Do To Fix This Issue?
There are a number of items you would need to address in relation to this, in order:
- Errors In Your Website:
- If there any errors in the underlying code or function of your website this will cause bottlenecks and/or unexpected operation which could affect visits to your website and hold connections open for longer.
- This would especially be the case when an error causes the process for that connection/visit to loop until the timeout value is reached; if you website is getting higher traffic this will compound the issue.
- Ensure Your Website Is Efficiently Cached (Where Possible):
- For the likes of content that is dynamically generated on websites - Wordpress and the like, you must implement in-website caching and optionally external caching to reduce the amount of time the website spends delivering content and the connections remain open.
- Essentially, the lesser the Webspace has to deliver in requests the quicker the connections will close and free up for subsequent requests but as a happy side effect the delivery of the website will be quicker for visitors also.
- Note that websites that have caching enabled but do not have .htaccess rules to assist with caching will not be as efficient at delivering content with them and as a result may be negatively impacting load times on your website; you must utilize .htaccess rules.
- For instance, in Wordpress you can use the likes of WP Super Cache (in Expert Mode).
- You should consult with your Web Developer on this or otherwise our Web Developers may be able to assist with implementing caching - in the likes of Wordpress site.
- Implement External Caching Or CDN Services For Your Website:
- If you can offload the serving of some content via a CDN system, such as images, this will then free up connections that would have otherwise been required to serve that content.
- We would not directly support these services, where they would be Third Party, and note they may also require configuration to suit your website so it would be advised you take caution when implementing them; review with your Web Developer beforehand.
- Depending on the use case and configuration of your website/data, you can also host content on the likes of a Cloud VM/Dedicated server with us.
- Deter Malicious And Brute-Force Traffic:
- It can be a case that attackers may try to obtain access to your website for malicious reasons: unfortunately, this is common place on the internet but you can take steps to deter this traffic.
- For instance, for the likes of Wordpress you can use Wordfence or otherwise you can put in blocking rules in .htaccess files (or use any means that suits your requirements).
- Overall, you would be best to stop this traffic from getting to the Webspace in the first place which would require you to block the traffic at an external service like Cloudflare or Sucuri; those are Third Party systems that we would not support directly but our customers have used.
- If you have gone through that, refer to the following (which is below also):
The Limits On Webspaces, On Our Shared Hosting Subscriptions
The limits differs depending on what Shared Hosting subscription you have for that Webspace:
- Minimus:
- Up to 30 Domains/Webspaces.
- 50 maximum Concurrent Connections, per Webspace
- Medius:
- Up to 60 Domains/Webspaces.
- 100 maximum Concurrent Connections, per Webspace
- Maximus:
- Up to 90 Domains/Webspaces.
- 150 maximum Concurrent Connections, per Webspace
You can upgrade from the Minimus and Medius subscriptions - as far as Maximus, to obtain the higher limits but you cannot obtain more than the limits imposed per subscription.
How Many Visitors Can Be On My Website At Any One Time?
You should note that the concurrent connection limit does not refer to the amount of visitors you can have on your website, rather it refers to the number of requests/connections to the Webspace that have been opened by a source - where the source can be any of and not limited to:
- Public facing visitors to your website, viewing and using your website.
- Visits from yourself to the website, while reviewing and working on the website.
- Search Engine Indexing bots, where they will scan you website for changes to add to the index.
- Other types of bots, there are many types of bots gathering information for the internet.
- Other types of traffic, including brute-force/malicious traffic.
You should note that it is possible for a source to open multiple connections - not just one, and often a Web Browser's Tab (or window) can open up to eight connections at a time in order to fetch the data from your website.
What Are The Connections For?
Each connection will be opened. and held open, until the source has completed the retrieval of the requested data from your Website/Webspace via that connection; while the connection is held open it will reduce the allowable limit by one connection.
The data, in this context, can be anything that is on your website i.e:
- The HTTP output from your website - which is typically one connection starting off.
- Stylesheet files on your website.
- JavaScript files on your website.
- Images on your website.
- Videos and streaming media (see note below).
- Any other files that are referenced by your website's output.
What Are Webspaces? Is That Not Just My Website?
Not necessarily as it is possible for you to have a multiple of your domains/websites in the same Webspace location, where the Webspace is a file location for your files - think of it like a set of folders/files in a single filing cabinet.
Each Webspace has operating limits imposed on it which is shared by all the domains listed in that Webspace, for this reason you can and should store each domain in it's own Webspace. You do not need to purchase a subscription for each Domain/Webspace as you can have multiple Webspaces on a subscription, albeit there is a limit on the amount of Webspaces you can have depending on the subscription you have.
You can contact us via our Helpdesk - help@blacknight.com, if you are not sure how to determine which domains are in which webspace or how to split them into their own Webspaces if required.
I Have Done That, I Am Still Getting The "Resource Limit Is Reached" Message?
At this point, the issue is likely due to higher traffic than typical on your website which can be due to:
- Website Launch, where the website has been promoted to launch at a date/time.
- Posts made on Social Media, or traffic originating from Social Media due to popularity.
- Competitions or Offers on the website, where traffic can be driven via external sources.
- TV Appearances, where the website is showcased or mentioned and traffic is driven.
- Radio show announcements, where the website is showcased or mentioned and traffic is driven.
- Advertisements of the website.
- Any other target driven traffic.
The issue with all of the above is how quick the traffic goes to the Webspace all at once not how much traffic you get overall from the event; if spread out over the course of the day/week then there would be lesser chance for the concurrent connection limit to be reached.
If you are expecting higher traffic based on the above, or expect that traffic will be higher on occasion and you would not know when it may be, then you will need to look at hosting your website on a capable Cloud VM or Dedicated server to cater for the traffic requirements of the website; or at the very least, upgrade to the Maximus subscription for the 150 concurrent connections.
Very Important Note:
If you are carrying out a launch, competition, promoting on Social Media or TV/Radio etc. and know of this in advance - in the order of days to a week, then it would be highly advised to move the website to a Cloud VM - the highest plan available, or a Dedicated server, to cater for the expected traffic. We would advise that you contact us as soon as you are aware of this event so we can discuss what may be required, costing of the same and also have enough time to process the move overall.
A Note On Video/Steaming Media On Your Website
It would be advised that you store and host any streaming media that is delivered via your website on an external system - such as a Cloud VM/Dedicated server with us, or a service that is designed to cater for and deliver those resources - the following are but some examples (what you choose to use is up to you):
- Videos: YouTube, Vimeo; etc..
- Music/Podcasts etc.: BuzzSprout, Soundcloud, etc..
There are two very good reasons for this suggestion:
- Concurrent Connections
- A connection will be held open for any resource until it has completed download.
- This means for the duration of the stream, a connection will be tied up by the requester.
- If you have higher traffic on these streams the connection limit will be reached quicker.
- Bandwidth Consumption
- Our Shared Hosting subscriptions have bandwidth limits: 200GB, 400GB, 600GB (respectively).
- Streaming media uses up a substantial amount of bandwidth in comparison to images etc..
- The bandwidth can be quickly consumed - noting there may be fees for over usage.
Additional Support
As always, should you require more assistance in relation to this issue, please contact our Helpdesk explaining your issue - and what you have done to this point, and we will be happy to assist you further.
Please see our full contact information, on our main website: Contact Us.
Alternatively, email help@blacknight.com for assistance.
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