Part of any self-healing system must be a mechanism that allows the software in the system to be upgraded. It is simply not realistic to assume that there would be no bugs in software nor any need to add new functionality. This paper studies some work that has been done in solving the problems related to the dynamic upgrade (or update) of the software. We assume that the system has to serve the...

Based on our previous experience we want to compare the performance between five hypervisors: XEN-PV, XENHVM,Open-VZ,KVM-FV,KVM-PV We have simulated the migration of a virtual machine by using a warning failure approach. Based on some experiments we have compared CPU Consumption, Memory Utilization, Total Migration Time and Downtime. We have also tested the hypervisor’s performance by changing ...

Unavailability in distributed enterprise systems is usually the result of planned events, such as upgrades, rather than failures. Major system upgrades entail complex data conversions that are difficult to perform on the fly, in the face of live workloads. Minimizing the downtime imposed by such conversions is a time-intensive and error-prone manual process. We propose upgrades-as-a-service, a ...

OVERVIEW For today’s storage area networks (SANs), analyzers are indispensable for finding and correcting network problems. Analyzers supply SAN managers with a view into the traffic traversing their networks and allow them to quickly troubleshoot everything from bad cables to system failures. Connecting an analyzer to a SAN requires inline installation, that is, placing the analyzer on the lin...

One important performance measure for routing protocols is packet delivery. An ideal routing protocol should quickly adapt to topological changes and deliver packets as long as any path to the destination exists. In this paper, we examine the packet delivery performance in a network running the BGP routing protocol when a destination may be disconnected from time to time. We develop two metrics...

In order to reduce system outages and the associated downtime cost caused by the “software aging” phenomenon, we propose to use software rejuvenation as a proactive system maintenance technique deployed in a CMTS (Cable Modem Termination System) cluster system. Different rejuvenation policies are studied from the perspective of implementation and availability. To evaluate these policies, stocha...

Feature engineering—developing a set of values that effectively describe raw data for a machine learning task—can be a lengthy, repetitive process. Further, good features for one learning task may not be suitable for another, so creating effective features can largely be a process of trial-and-error. Difficulties aside, however, the ultimate success of a trained system depends on the ability of...

model is established so that client systems will not function without the server, and the server is not available, department members will sit around unable to use the system — just as we did twenty years ago when the mainframe was down. Many of us have memories of those days and no desire to return to them. The risk of server downtime is substantial. A good system administrator is the best pro...

System reliability is a major challenge in system design. Unreliable systems are not only major source of user frustration, they are also expensive. Avoiding downtime and the cost of actual downtime make up more than 40% of the total cost of ownership for modern IT systems. Unfortunately, with the large component count in today’s large-scale systems, failures are quickly becoming the norm rathe...

With redundant hardware, it is rare that a disk failure results in downtime at the system level. System failures do sometimes occur, typically as a sequence of very rare events that leads to a catastrophic failure. This case describes how a combination of hardware and firmware failures, along with human error, led to the failure of a redundant disk storage unit, which in turn affected several e...