Modern CPUs operate significantly faster than memories. For instance, a 4.5 GHz x64 CPU operates 30 times faster than a 6000 MHz DDR5 memory of CAS Latency 36. Adding latencies incurred by the bus and memory coherency protocols, CPU access to memory could be 100 times slower than CPU access to registers. To mitigate …

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Given a non-decreasing array and a target value, we can find the target in the array in logarithmic time using binary search. My first programming language is C++ and the C++ Standard Template Library (STL) provides two functions for this task. iterator lower_bound(first, last, value) returns the smallest index with a …

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Problem An event consists of multiple properties, each defined as a key-value pair, where the key is a string and the value is of a primitive type such as numbers or strings. Importantly, each event must include a mandatory 'Name' property. Given a list of events, the task is to count the number of events based on …

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Every Go program has a runtime. The runtime implements garbage collection, concurrency, stack management, and other critical features. We can configure the runtime by setting variables. In this post, we will look at GOMAXPROCS, a variable that configures concurrency. You may get free performance boost by setting …

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We plan to load test our product before public Beta, with two goals in mind. Find out bottlenecks: figure out road maps of performance improvement and prepare for oncalls. Understand how much workload we can support with fixed resources. This shapes the pricing strategy and determines number of Beta partners to …

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I implemented a job scheduler at work recently. Each job has a unique ID and an expiration time. The job ID is immutable while the expiration time may change. The job scheduler schedules the job of the earliest expiration time. Go comes with heap.Interface and map. My first implementation uses a hashmap and a slice …

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A defer statement invokes a function just before the surrounding function returns. Multiple defers within a function are executed in reverse order of their calls, following the Last In First Out (LIFO) principle. Defer is commonly used to ensure resource cleanup, regardless of the function's success or failure. For …

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At iheartjane, we use Go web server to serve Ad requests. After some time in production, we noticed a lot of “context canceled” error logs. The following screenshot of CloudWatch Log Insights query shows the frequency of “context canceled” errors. It left us puzzled about the underlying causes of these context cancels. …

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Identifying unique entities is a frequent requirement in software development. For instance, assigning a unique ID to each Ad impression enables us to link related events for billing and analysis. However, generating unique IDs becomes challenging when dealing with large distributed systems. In this survey, we explore …

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We set up test doubles when it is difficult or impossible to use real objects due to complexity or external dependencies. In Go, an interface is a collection of method signatures that define a set of behaviors. With interfaces, it is easy to create test doubles in Go. However, should you write test doubles on your own, …

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