service level objectives

Starting Observability



Starting Observability

In the ever-evolving landscape of technology, the complexity of modern systems continues to increase. As software developers, system administrators, and IT professionals, we are constantly faced with the challenge of ensuring the smooth operation of these intricate systems. This is where observability comes into play. In this blog post, we will delve into the concept of observability, its significance in modern systems, and the benefits it brings to the table.

Observability is the ability to gain insight into the inner workings of a system through its outputs, allowing us to infer its internal state. Unlike traditional monitoring, which focuses on measuring predefined metrics, observability takes a more holistic approach. It emphasizes the collection, analysis, and interpretation of various data points, enabling us to gain a deeper understanding of our systems.


Highlights: Starting Observability

  • A New Paradigm Shift

To support the new variations, your infrastructure is amid a paradigm shift. As systems become more distributed and complex, methods for building and operating them are evolving, making network visibility into your services and infrastructure more critical than ever. This leads you to adopt new practices, such as Starting Observability and implementing service level objectives (SLO).

  • The Internal States

Observability aims to provide a level of introspection to understand the internal state of the systems and applications. That state can be achieved in various ways. The most common way to fully understand this state is with a combination of logs, metrics, and traces as debugging signals—all of these need to be viewed as one, not as a single entity.

So, you have probably come across the difference between monitoring and Observability. But how many articles have you crossed with guidance on starting an observability project?


For additional pre-information, you may find the following helpful

  1. Observability vs Monitoring
  2. Distributed Systems Observability
  3. WAN Monitoring
  4. Reliability In Distributed System


Back to basics with Starting Observability

Observability is critical for building, changing, and understanding the software that powers complex modern systems. Teams that adopt Observability are much better equipped to ship code swiftly and confidently, identify outliers and aberrant behaviors, and understand every user’s experience. In that case, Observability for software systems measures how well you can understand and explain any state your system can get into, no matter how novel or bizarre.


Observability Engineering
Diagram: Observability engineering. The starting point.

The Three Pillars of Observability

Observability rests upon three main pillars: logs, metrics, and traces. Logs capture textual records of system events, providing valuable context and aiding in post-incident analysis. Metrics, on the other hand, are quantitative measurements of system behavior, allowing us to track performance and identify anomalies. Lastly, traces provide a detailed view of request flows and interactions between system components, facilitating troubleshooting and understanding of system dependencies.

The Power of Proactive Maintenance

One of the key advantages of observability lies in its ability to enable proactive maintenance. By continuously monitoring and analyzing system data, we can identify potential issues or anomalies before they escalate into critical problems. This proactive approach empowers us to take preventive measures, reducing downtime and improving overall system reliability.

Unleashing the Potential of Data Analysis

Observability generates a wealth of data that can be harnessed to drive informed decision-making. By leveraging data analysis techniques, we can uncover patterns, identify performance bottlenecks, and optimize system behavior. This data-driven approach empowers us to make data-backed decisions that enhance system performance, scalability, and user experience.

The Immediate Starting Strategy

Start your observability project in the middle, not in the fridge, and start with something important. There is no point in starting an observability project on something no one cares about or uses that much. So choose something that matters, and the result will be noticed. But, on the other hand, something that no one cares about will not attract any interest from stakeholders.


Service level objectives (SLO)

So, to start an observability project on something that matters and will attract interest, you need to look at metrics that matter, which will be with Service Level Objectives (SLOs). With service level objectives, we are attaching the needs of the product and business to the needs of the individual components finding the perfect balance for starting observability projects.

The service level objective aggregates over time and is a mathematical equivalent of an error budget. So over this period, am I breaching my target? If you exceed your SLO target, your users will be happy with the state of your service.

If you are missing your SLO target, your users are unhappy with the state of your service. It’s as simple as that. So the SLO is the target’s goal over a measurement period. The SLO includes two things: it contains the target and a measurement window. Example: 99.9% of checkout requests in the past 30 days have been successful. Thirty days are the measurement window.  


    • Key Point: Take advantage of Error Budgets

Once you have determined your service level objectives, it would help to look at your error budgets. Nothing can always be reliable, and it’s ok to fail. This is the only way to perform tests and innovate to meet better user requirements, which is why we have an error budget. An error budget references a budget of failure that you are allowed to have per hour or month.

It is the amount of unreliability we will tolerate, as we need a way to measure that. So once you know how much of the error budget you have left, you can take more risks and roll out new features. They help you balance velocity and reliability. So the practices of SLO and error budgets prioritize reliability and velocity.


    • Key Point: Issues with MTTR

SLO is an excellent way to start and win. This can be approached on a team-by-team basis. It’s a much more accurate way to measure reliability than Mean Time to Recovery (MTTR).

The issue with MTTR is that for every incident, you measure the time it takes to resolve it. However, it can be subject to measurement error. The SLO is harder to cheat and a better way to measure.

So we have key performance indicators ( KPI), service level indicators (SLI), and service level objectives (SLO). These are the first ways to implement Observability, not just look at the KPI. First, you should monitor KPI and SLx along with the system’s internal state. From there, you can derive your service level metrics. And these will be the best place to start an observability project.


What is a KPI and SLI: User experience

The key performance indicator is tied to system implementation, and it conveys health and performance and may change if there are architectural changes to the system. For example, database latency would be a KPI.   In contrast to KPI, we have service level indicators. An SLI is a measurement of your user experience. And can be derived from several signals.

The SLI does not change unless the user needs to change it. It’s a metric that matters most to the user. This indicator tells you if your service is acceptable or not. So this line tells you if you have a happy or sad user. It’s a performance measurement, like a metric that describes a user’s experience. 


  • Types of service level indicators

An example of an SLI would be availability, latency, correctness, quality, freshness, and throughout. So we need to gather these metrics, which can be supposed by implementing several measurement strategies such as application-level metrics, logs processing, and client-side instrumentation.

So, if we look at an SLI implementation for availability, it would be, for example, the portion of HTTP GET request for /type of request.

The users care about SLI and not KPI. I’m not saying that database latency is not essential. You should measure it and put it in a predefined dashboard. But users don’t care about database latency or how quickly their requests can be restored.

Instead, the role of the SLI is to capture the user’s expectation of how the system behaves. So, if your database is too slow, you have to front your database with a cache. So the cache hit ratio becomes a KPI, but the user’s expectations have not changed. 


Starting Observability Engineering

Good Quality Telemetry

You need to understand the importance of high-quality telemetry. You must adopt this carefully, the first step to good Observability. So it would be best to have quality logs and metrics and a modern approach such as Observability, which is required for long-term success. For this, you need good Telemetry; without good telemetry is going to be hard to shorten the length of outages. 

Instrumentation: OpenTelemetry 

The first step to consider is how your applications will omit telemetry data. For instrumentation of both frameworks and application code, OpenTelemetry is the emerging standard. With OpenTelemetry’s pluggable exporters, you can configure your instrumentation to send data to the analytics tool of your choice.

In addition, OpenTelementry helps you with distributed tracing, which helps you understand system interdependencies. Those interdependencies can obscure problems and make them challenging to debug unless the relationships between them are clearly understood.

distributed tracing example
Diagram: Distributed tracing example.


Data storage and analytics

Once you have high-quality telemetry data, you must consider how it’s stored and analyzed. Data storage and analytics are often bundled into the same solution, depending on whether you use open-source or proprietary solutions.

Commercial vendors typically bundle storage and analytics. These solutions will be proprietary all-in-one solutions, including Honeycomb, Lightstep, New Relic, Splunk, Datadog, etc.

Then we have the open-source solutions that typically require separate data storage and analytics approaches. These open-source frontends include solutions like Grafana, Prometheus, or Jaeger. While they handle analytics, they all need an independent data store to scale. Popular open-source data storage layers include Cassandra, Elastic, M3, and InfluxDB.


  • A final note: Buy instead of building?

Knowing how to start is the most significant pain point; deciding to build your observability tooling vs buying a commercially available solution quickly proves a return on investment (ROI). You will need to buy it if you don’t have enough time.

I prefer buying to get a quick recovery and stakeholder attention. While at the side, you could start to build with open-source components.

Essentially, you are running two projects in parallel. You buy to get immediate benefits and gain stakeholder attraction, and then on the side, you can start to build your own., which may be more flexible for you in the long term.


Observability has become an indispensable tool in the realm of modern systems. Its holistic approach, encompassing logs, metrics, and traces, enables us to gain deep insights into system behavior. By adopting observability practices, we can proactively maintain systems, analyze data to drive informed decisions, and ultimately ensure the smooth operation of complex systems in today’s technology-driven world.


Matt Conran: The Visual Age
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