How a Tap or SPAN Choice Impacts APM
May 22, 2019

Keith Bromley
Ixia

Share this

For application performance monitoring (APM), many in IT tend to focus a significant amount of their time on the tool that performs the analysis. Unfortunately for them, the battle is won or lost at the data access level. If you don’t have the right data, you can’t fix the problem correctly.

This viewpoint is backed up by an APMdigest post back in August where Jim Frey cited some critical survey research. The research showed that "26% reported that their biggest challenge with incident response is that data exists, but they can’t access or analyze it easily." Key point – you need access to the right data at the right time to solve your problems.

This begs the question — how do I get the right data access?

The best source of data is from a network tap. A tap makes a complete copy of ALL the data passing through it. It is a passive device, so it does not alter any of the data and has a negligible effect on transmission time.

Taps are great because they are "set and forget." You simply plug the device into the network with a one-time disruption and you are done. No programming is required. Best of all, you can place taps anywhere in the network that you need data from — ingress, egress, remote offices, etc.

The one drawback to using taps is that if you install lots of them (which you will want to do), the amount of data feeds can overload the input ports to your APM tools. However, this issue is easily resolved by installing a network packet broker (NPB) to aggregate the data from the taps, filter the data as necessary, and then send that data on to the APM tool. This eliminates the overcrowding of the data ports on your APM tool.

An alternative to a tap is to use a mirroring port (also referred to as a SPAN port) off of your network switches. However, this is not recommended. One reason is that these ports are active devices, i.e. they can materially change data packet characteristics as the packets flow through the device. This is especially important when using data from these ports to diagnose problems.

In addition, bad packets (i.e. malformed packets) are dropped by the SPAN port. This ends up giving you a "digital view" of the situation, i.e. everything is fine and then there is a problem. Missing packets that could show degradation prior to data loss (which could have been useful to create a quicker diagnosis) is missing, along with any context as to what was happening before the problem began.

In the end, optimum data capture can be achieved using a tap and NPB. This results in a faster mean time to repair (MTTR).

Keith Bromley is Senior Manager, Solutions Marketing at Ixia Solutions Group, a Keysight Technologies business
Share this

The Latest

April 01, 2020

The role of the CIO is evolving with more of a focus on revenue and strategy, according to the 2019 Global CIO Survey from Logicalis ...

March 31, 2020

Organizations face major infrastructure and security challenges in supporting multi-cloud and edge deployments, according to new global survey conducted by Propeller Insights for Volterra ...

March 30, 2020

Developers spend roughly 17.3 hours each week debugging, refactoring and modifying bad code — valuable time that could be spent writing more code, shipping better products and innovating. The bottom line? Nearly $300B (US) in lost developer productivity every year ...

March 26, 2020

While remote work policies have been gaining steam for the better part of the past decade across the enterprise space — driven in large part by more agile and scalable, cloud-delivered business solutions — recent events have pushed adoption into overdrive ...

March 25, 2020

Time-critical, unplanned work caused by IT disruptions continues to plague enterprises around the world, leading to lost revenue, significant employee morale problems and missed opportunities to innovate, according to the State of Unplanned Work Report 2020, conducted by Dimensional Research for PagerDuty ...

March 24, 2020

In today's iterative world, development teams care a lot more about how apps are running. There's a demand for fixing actionable items. Developers want to know exactly what's broken, what to fix right now, and what can wait. They want to know, "Do we build or fix?" This trade-off between building new features versus fixing bugs is one of the key factors behind the adoption of Application Stability management tools ...

March 23, 2020

With the rise of mobile apps and iterative development releases, Application Stability has answered the widespread need to monitor applications in a new way, shifting the focus from servers and networks to the customer experience. The emergence of Application Stability has caused some consternation for diehard APM fans. However, these two solutions embody very distinct monitoring focuses, which leads me to believe there's room for both tools, as well as different teams for both ...

March 19, 2020

The 2019 State of E-Commerce Infrastructure Report, from Webscale, analyzes findings from a comprehensive survey of more than 450 ecommerce professionals regarding how their online stores performed during the 2019 holiday season. Some key insights from the report include ...

March 18, 2020

Robinhood is a unicorn startup that has been disrupting the way by which many millennials have been investing and managing their money for the past few years. For Robinhood, the burden of proof was to show that they can provide an infrastructure that is as scalable, reliable and secure as that of major banks who have been developing their trading infrastructure for the last quarter-century. That promise fell flat last week, when the market volatility brought about a set of edge cases that brought Robinhood's trading app to its knees ...

March 17, 2020

Application backend monitoring is the key to acquiring visibility across the enterprise's application stack, from the application layer and underlying infrastructure to third-party API services, web servers and databases, be they on-premises, in a public or private cloud, or in a hybrid model. By tracking and reporting performance in real time, IT teams can ensure applications perform at peak efficiency — and guarantee a seamless customer experience. How can IT operations teams improve application backend monitoring? By embracing artificial intelligence for operations — AIOps ...