Artikelen met de "Technisch" tag

Incident summary

During routine maintenance, the movement of a network cable brought to light a dormant issue in one networking component, resulting in a degraded connection. Later, while trying to fix this issue, an unrelated network cable was accidentally disconnected for a few seconds. As our infrastructure is built redundantly, both incidents should have had no impact. However, a software malfunction prevented another connection to take over on both system. This put them into an unstable state that resulted in a partial unavailability of our services between 15:20 and 19:45 CEST.

Resolution...

It is now possible to use cloud-init with our VPS's. Cloud-init scripts define what needs to be done immediately after a VPS is started for the first time. These files can be used to automate the setup of a VPS. This can range from small tasks — like configuring the machine or adding more users — to more complex tasks like installing software.

Cloud-init is a technology that is supported by many cloud providers. In addition to cloud-init scripts that you might find anywhere on the internet, Greenhost offers a repository with scripts that you can use to automate certain steps in setting up...

What follows is a relatively detailed and technical description of the reasons for the outage. Because we understand not everyone wants or understands this much detail we added a simpler and shorter summary of the problem:

There was a problem with the devices (switches) that regulate the (redundant) internet (network) connections to our data centre. In trying to solve this isolated problem unfortunately a feedback loop occurred that clogged the multiple connections.

We have multiple connections going to the data centre to prevent losing access to our machines, however this issue managed to...

Update 19 januari 2018 15:22

Al onze systemen zijn gepatched en bijgewerkt. Vanaf nu werken we verder aan de langetermijngevolgen van de CPU-bugs.

Update 12 januari 2018 17:30

Op een paar uitzonderingen na zijn al onze klantsystemen intussen geüpdatet. Volgende week gaan we verder met updaten van onze interne systemen. Tijdens het updaten kan er een kleine onderbreking van onze dienstverlening ontstaan. Vandaar dat de updates zullen plaatsvinden buiten de reguliere uren. Wij houden je hiervan op de hoogte.

Update 9 januari 2018 18:18

Al onze VPS klanten hebben e-mail ontvangen met de volgende...

Everyone has had the experience, staring at a browser and wondering why a particular website was taking such a long time to load. What makes websites slow can depend on several factors. Is the code efficient? Is the webserver efficient? How efficient is the storage? As a hosting provider mindful of sustainability, we are always trying to improve performance on our side, while also keeping redundancy in place as much as possible. Recently, we noticed one of our SQL servers was getting slower over time for no apparent reason, so we dug a little deeper to see how we could improve its performance.

Building a router with Linux is a viable alternative to commercial products in many applications. In this article, we explore the process of optimising Linux for the best packet-forwarding performance by exploiting symmetric multiprocessing (SMP) and Ethernet interfaces with multiple queues. We take advantage of the Linux kernel features known as Receive Packet Steering (RPS), Transmit Packet Steering (XPS), and IRQ affinity.