How to troubleshoot remote write issues in Prometheus

The post delves into troubleshooting remote write issues in Prometheus, emphasizing the complexities of its tunable settings and the potential for data loss. Initially, remote write duplicated scraped samples, but challenges with fixed-size buffers led to data drops or memory overloads during disruptions. To mitigate data loss, Prometheus now reads data from its write-ahead log, offering a 2- to 3-hour disk buffer, reducing reliance on large in-memory buffers. The text explains key metrics for diagnosing remote write issues, such as those indicating how far remote write is falling behind or how many shards are active. It also outlines configuration parameters like shard numbers and batch sizes to manage throughput and network load. The post concludes by highlighting ongoing efforts to enhance remote write's reliability and encourages community engagement for feedback and contributions.