Resolve the 500 Internal Server Error for PHP 7.4 with IIS on Windows Server for WordPress 5.31

Resolve the 500 Internal Server Error for PHP 7.4 with IIS on Windows Server for WordPress

Many of my readers will know I run a tight ship when it comes to keeping my blog infrastructure up to date and as secure as I can. This means, among other things, I keep my operating system recent and patched. The same goes for my MySQL database, PHP versions, and WordPress + plugins.

Recently I wanted to upgrade to PHP 7.4 that was just released and should be compatible with WordPress 5.3.1.

Resolve the 500 Internal Server Error for PHP 7.4 with IIS on Windows Server

But once I switched to PHP 7.4 my site responded with the dreaded 500 Internal Server Error. Instead of going trial and error I decided to zoom in fast to the root cause to resolve the 500 Internal Server Error for PHP 7.4 with IIS on Windows Server.

Troubleshooting steps

The fasted way to figure out what issues PHP has is to open an elevated command prompt and navigate to the install path of your PHP version. For me, that would be C:\Program Files\PHP\php-7.4.0-nts-Win32-vc15-x64. Note that IIS with requires the non thread safe version of PHP.

Once there run php -m

I got greeted by this warning.

PHP Warning: ‘vcruntime140.dll’ 14.0 is not compatible with this PHP build linked with 14.16 in Unknown on line 0

Resolve the 500 Internal Server Error for PHP 7.4 with IIS on Windows Server

That ‘s clear enough. I need to upgrade my Visual C++ runtime. I have but I need a more recent version. Basically the one for Visual ++ 2105-2019. You can grab those here for both x64 and x86.

https://aka.ms/vs/16/release/VC_redist.x64.exe
https://aka.ms/vs/16/release/VC_redist.x86.exe

I tend to install both. Just in case I have an issue with x64 PHP I can try the x86 version to try and resolve it, Normally I default to x64 bit and for the past years that has worked very well.

Once I had installed those my blog sprung back to life and that was it. If you run php -m again you won’t see the warning anymore. No need to switch themes (I have a simple one that has longevity). I also dd not have to empirically disable/enable plugins. I select quality free and modern plugins that I keep up to date or replace when needed. So, for me, that was the fix. Since most troubleshooting guided don’t start here, give it a shot. The HTTP Error 500.0 – Internal Server Error is an annoying one to troubleshoot. The PHP error log might not tell you anything as it goes wrong before it can log anything and enabling more detailed error handling does not always pinpoint something precisely. It might even send you on a wild goose chase.

Resolve the 500 Internal Server Error for PHP 7.4 with IIS on Windows Server
Not very specific is it?

If you did change the feature settings for the error pages for your site to get more detailed information to “Detailed errors” don’t forget to set it back. Configure it back to the default of  “Detailed error for local requests and custom error pages for remote requests” or your custom pages. You don’t want the details shown publically.

That’s it. I hope it helps someone who tries to resolve the 500 Internal Server Error for PHP 7.4 with IIS on Windows Server

November 2019 updates caused Windows Server 2012 reboot loop

Introduction

Some laggards that still have some Windows Server 2012 virtual machines running got a bit of a nasty surprise last weekend. A number of them went into a boot loop. Apparently the November 2019 updates caused Windows Server 2012 reboot loop. Well, we have dealt with update issues before like here in Quick Fix Publish : VM won’t boot after October 2017 Updates for Windows Server 2016 and Windows 10 (KB4041691). No need to panic.

Symptoms

Not all Windows Server 2012 virtual machines were affected. We did not see any issues with Windows Server 2012 R2, 2016 or 2019. Well the symptom is a reboot loop and below I have a sequence of what it looked like visually.

November 2019 updates caused Windows Server 2012 reboot loop
Restarting
Looking good so far …
OK, stage 2 of 4 … stlil seems OK.
November 2019 updates caused Windows Server 2012 reboot loop
Could still be OK … but no, its starts again in an endless loop.

So what caused this Windows Server 2012 reboot loop?

Fix

We turned of the virtual machines on which the November 2019 updates caused Windows Server 2012 reboot loop. We started them up again in “Safe mode” which completed successfully. Finally, we then did a normal reboot and that completed as well. All updates had been applied bar one. That was the 2019-11 Servicing Stack Update for Windows Server 2012 (KB4523208).

We manually installed it via Windows update and that succeeded.

When reading the information about this update https://www.catalog.update.microsoft.com/ScopedViewInline.aspx?updateid=5fa2a68f-e7cd-43c7-a48a-5e080472cb77 its states it need to be installed exclusively.

Maybe that was the root cause. It got deployed via WSUS with the other updates for November 2019.

Anyway, all is well now. I remind you that we have at least 2 ways of restoring those virtual machines. In case we had not been able to fix them. Have known good backups and a way to restore them people.

Conclusion

We fixed the issue and patched those servers completely. So all is well now. Except for the fact that they now , once more, have been urged to get of this operating system asap. You don’t go more than N-2 behind. It incurs operational overhead and risks. They did not test updates against this old server VM and got bitten. Technology debt without a plan is never worth it.

Licensed Replay Manager Node Reports being unlicensed

Licensed Replay Manager Node Reports being unlicensed

I was doing a hardware refresh on a bunch of Hyper-V clusters. This meant deploying many new DELL PowerEdge R740 servers. In this scenario, we leverage SC Series SC7020 AFA arrays. These come with Replay Manager software which we use for the hardware VSS provider. On one of the replaced nodes, we ran into an annoying issue. Annoying in the fact that the licensed Replay Manager Node reports being unlicensed in the node’s application event log. The application consistent replays do work on that node. But we always get the following error in the application event log:

Product is not licensed. Use Replay Manager Explorer ‘Configure Server’ or  PowerShell command ‘Add-RMLicenseInfo’ to activate product license.

Product is not licensed. Use Replay Manager Explorer 'Configure Server' or  PowerShell command 'Add-RMLicenseInfo' to activate product license.

On the Replay Manager Explorer, we just see that everything is fine and licensed. Via the GUI or via PowerShell we could not find a way to “re-license” an already installed server node.

What we tried but did not help

This is not a great situation the be in, therefore we need to fix it. First of all we removed the problematic node from Replay Manager explorer and tried to re-add it. That did not help to be able to relicense it. Uninstalling the service on the problematic node also did not work. Doing both didn’t fix it either. We need another approach.

The fix

The trick to fixing the licensed Replay Manager Node reports being unlicensed is as follows. Stop the “Dell Storage Replay Manager Service” service.

Delete (or rename if you want to be careful) the Compellent folder under C:\ProgramData

Restart the “Dell Storage Replay Manager Service” service. As a result you will see the folder and the files inside being regenerated. Wait until the temp files (ReplayManager.db-shm and ReplayManager.db-wal) of this process are gone.

Open up Replay Manager Explorer or relaunch it for good measure if still open. Connect to the problematic node. Navigate to “Configure Server” On the license tab it reports that it is unlicensed. Now enter the license code and request confirmation (Activate via Internet) or Activate via phone.

The node is now licensed again.

The node is licensed again. The system needs to be configured.

The image above shows the node is licensed again. You now need to configure the system again because that info is lost. For that, enter the username and password for your SC Arrays and add the correct node.

We now test creating a replay! Most importantly, we check the node’s application event log. The error Product is not licensed. Use Replay Manager Explorer ‘Configure Server’ or  PowerShell command ‘Add-RMLicenseInfo’ to activate product license. has gone!

We only see the 3 informational entries (prepared, committed, successful) associated with a successful and completed replay.

Above all, I hope this helps others who run into this.

Force Mellanox ConnectX-4 Lx 25Gbps to 10Gbps speed

Introduction

As you might remember I wrote a blog post about SFP+ and SFP28 compatibility. In this i discuss future proofing your network investments and not having to upgrade everything all at once. One example is that buying 25Gbps NICs when your main network infrastructure is still on 10Gbps is not an issue. 25Gbps normally handles 10Gbps well so you don’t have do replace all parts in the fabric at the same time but you can start with either the network fabric or the server NICs. It’s a way of future proofing the investments you make today.

When installing Mellanox ConnectX-4 Lx 25Gbps NICs in a bunch of servers we hit an issue when connected them to the DELLEMC N4000 10Gbps switches. The intent is to replace these with 25/50/100Gbps in the future.

The links did not come up.

The links did not come up. The switch ports are normally forced 10 Gbps in our setups so we check that. The speed was indeed set fix to 10Gbps. When changing that to auto-negotiate the link would come up at 1Gbps.

Naturally you check everything from cabling to used transceivers (BCM84754 on the switches) but that all checked out. We also check the firmware on the switches to determine if they were up to date and perhaps a new version fixed a known issue related to this. But no hardware wise everything was up to date on the switches and on the NICs.

Note that these links worked fine when used with 10 Gbps cards like the ConnectX-3 Pro. The DELL branded transceivers on the switches were BCM84754 (Broadcom)

The fix: Force Mellanox ConnectX-4 Lx 25Gbps to 10Gbps speed

I do not need to tell you that when you want 10Gbps getting 1Gbps doesn’t fly well. The fix was easy enough. We put the switch ports back to 10Gbps fixed speed. Auto-negotiate doesn’t deliver. No worries we fix the ports anyway. We then used mlc5cmd.exe Mellanox tool to change the NIC ports from auto-negotiate to fixed.

On hosts with Mellanox Connect-X4 NICs you open an elevated command prompt.

Navigate to C:\Program Files\Mellanox\MLNX_WinOF2\Management Tools. Run the below command to check the current link speed.

mlx5cmd.exe -LinkSpeed -Name “MyNicName ” -Query

Note 10 and 25 Gbps are supported, so it’s autonegotiate.

We force the link speed to 10Gbps:

mlx5cmd.exe -LinkSpeed -Name “MyNicName ” -Set 10

Link speed is forced to 10Gbps

The link comes up at 10Gbps

Likewise you can force the link to 25Gbps. If you want to change it back to the default you can force the link speed to auto-negotiate again.

mlx5cmd.exe -LinkSpeed -Name “MyNicName” -Set 0

See https://community.mellanox.com/s/article/mlx5cmd-exe for more information on this tool.

Do note that the switch port also needs to be set to 10Gbps fixed. As you can see below the command will notify you when those are still on auto.

The change was done but still no uplink when the switch port isn’t fixed to 10Gbps.

Conclusion

So my statement hold true the path to 25/50/100Gbps is one you can do step by step with future proofing. You might run into some issues but these are normally fixable. I have shared with you how to fix failing or wrong speed negotiations on 25 Gbps RDMA NICs (Mellanox ConnectX-4 Lx) when connecting to 10Gbps ports. I’m pretty sure the same holds true for other models. I have also had cards where things work out of the box but don’t give up when you hit an issue. I hope this helps some of you out there.