We have created a site that is used across load balanced servers. Its using Umbraco 4.0.1 with file replication across folders (using Robocopy). This site is heavily used with administrators updating content throughout the day.
We've found that often when the administrator tries to pubish a new page, it causes an error which will not publish, and the only way to resolve this is to delete the umbraco.config, re-save the web.config and republish the umbraco site. We're having to do this a few times a day, which is not really an option.
We've also found that often publishing new pages on one server does not replicate over to the other server, even though they are using the same Umbraco database. Content in the database publishes automatically, but creating new pages etc do not necessarily copy across. This is intermittent. We've also tried logging in to Umbraco on one server and publishing a page; then logging into Umbraco on the second server and refreshing the cache. This tends to cause an error where you can no longer publish anything and again have to refresh the web.config file.
Any help would be very much appreciated, as these issues only seem to occur across load balanced sites.
A ton of improvements to load balancing have been made since 4.0.1. Both 4.0.2 and 4.0.3 have fixes for load balancing so I suggest that you try to upgrade to the latest version and see how that goes for a starter. You should also make sure that your application pools in IIS doesn't run in "web garden" mode which is not compatible with Umbraco and will cause cache issues.
Assuming you've got the firewalls, dns, routing, and other config stuff set up for umbraco to work in a load-balanced environment then there are a few things to look at:
1. Upgrade to umbraco 4.0.3, which has some load balancing fixes. That alone may resolve the issues.
2. Robocopy is really not a reliable approach. Ideally you'd use a SAN so all servers work against the same files. Next best would be DFS or a NAS. Least reliable is a file sync tool because they are not instantaneous and can have file-contention issues.
We've upgraded to Umbraco 4.0.3 in our test environment. It looks as though we can't create any pages at all that publish, without having to resave the web.config file. Previously this was intermittent. It causes the 'Link to Document' field to be blank, instead of an aspx page, and causes XSLT errors on the site. The only way we've found to fix this is every time we publish something, to delete the umbraco.config and re-save the web.config. This is not just on load balanced servers (our dev environment is only on one server).
Also when we are trying to publish in advance using the 'Publish at', this does not work at all.
Do any of these things sound familiar? Any fixes you know of?
@Marco, we do not replicate the web.config across servers, as they have one item different in each which helps us understand which server we are on for logging purposes.
we have a similar problem on o one site. We have umbraco 4.0.3 instance on a load balanced configuration with dfs and excludind umbraco.config from replication. But we have the problems that when we pubblish a new node we can't see the link to document field and umbraco don't publish the nod at all!
Load Balance Issues
Hi there,
We have created a site that is used across load balanced servers. Its using Umbraco 4.0.1 with file replication across folders (using Robocopy). This site is heavily used with administrators updating content throughout the day.
We've found that often when the administrator tries to pubish a new page, it causes an error which will not publish, and the only way to resolve this is to delete the umbraco.config, re-save the web.config and republish the umbraco site. We're having to do this a few times a day, which is not really an option.
We've also found that often publishing new pages on one server does not replicate over to the other server, even though they are using the same Umbraco database. Content in the database publishes automatically, but creating new pages etc do not necessarily copy across. This is intermittent. We've also tried logging in to Umbraco on one server and publishing a page; then logging into Umbraco on the second server and refreshing the cache. This tends to cause an error where you can no longer publish anything and again have to refresh the web.config file.
Any help would be very much appreciated, as these issues only seem to occur across load balanced sites.
Cheers
Lisa
A ton of improvements to load balancing have been made since 4.0.1. Both 4.0.2 and 4.0.3 have fixes for load balancing so I suggest that you try to upgrade to the latest version and see how that goes for a starter. You should also make sure that your application pools in IIS doesn't run in "web garden" mode which is not compatible with Umbraco and will cause cache issues.
Hope this helps!
Assuming you've got the firewalls, dns, routing, and other config stuff set up for umbraco to work in a load-balanced environment then there are a few things to look at:
1. Upgrade to umbraco 4.0.3, which has some load balancing fixes. That alone may resolve the issues.
2. Robocopy is really not a reliable approach. Ideally you'd use a SAN so all servers work against the same files. Next best would be DFS or a NAS. Least reliable is a file sync tool because they are not instantaneous and can have file-contention issues.
cheers,
doug.
Hi Guys,
Thanks for the fast responses. I'll look to upgrade and see if this resolves the issues.
Many thanks
Lisa
When syncing files (using DFS), I usually exclude umbraco.config from replication so that each node handles its own cache file.
@Douglas: when using a SAN, which global (or parallel) file system would you suggest?
@Marco: That's also recommended as Umbraco handles updates to umbraco.config
Hi again,
We've upgraded to Umbraco 4.0.3 in our test environment. It looks as though we can't create any pages at all that publish, without having to resave the web.config file. Previously this was intermittent. It causes the 'Link to Document' field to be blank, instead of an aspx page, and causes XSLT errors on the site. The only way we've found to fix this is every time we publish something, to delete the umbraco.config and re-save the web.config. This is not just on load balanced servers (our dev environment is only on one server).
Also when we are trying to publish in advance using the 'Publish at', this does not work at all.
Do any of these things sound familiar? Any fixes you know of?
@Marco, we do not replicate the web.config across servers, as they have one item different in each which helps us understand which server we are on for logging purposes.
Thanks
Lisa
Sorry all. It seemed to be an incorrect setting in the Umbraco.config file.
Still having issues with 'Publish At' though.
I'll open another bug though, as it may not be to do with load balancing.
4.0.3 is looking good so far. Thanks!
Hi to all,
we have a similar problem on o one site. We have umbraco 4.0.3 instance on a load balanced configuration with dfs and excludind umbraco.config from replication. But we have the problems that when we pubblish a new node we can't see the link to document field and umbraco don't publish the nod at all!
why?
Thanks very much
gabriele
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