# Diagnosing Go Application Latency with strace and fsync

DevFeed: [Diagnosing Go Application Latency with strace and fsync](<https://devfeed.tech/articles/logging-can-be-tricky-15752.md>)

Original publisher: [Read original article](<https://developer.squareup.com/blog/logging-can-be-tricky>)

Author: Square Engineering

Published: 2014-09-22T16:07:00Z

Content type: article

Language: en

Sources: [Square Corner Blog RSS Feed](<https://devfeed.tech/sources/square-corner-blog-rss-feed.md>)

Topics: [Go Language](<https://devfeed.tech/topics/go-language.md>), [Latency](<https://devfeed.tech/topics/latency.md>), [debug](<https://devfeed.tech/topics/debug.md>), [IO](<https://devfeed.tech/topics/io.md>), [systems](<https://devfeed.tech/topics/systems.md>)

Tags: [cpu](<https://devfeed.tech/tags/cpu.md>), [debugging](<https://devfeed.tech/tags/debugging.md>), [engineering](<https://devfeed.tech/tags/engineering.md>), [filesystem](<https://devfeed.tech/tags/filesystem.md>), [go](<https://devfeed.tech/tags/go.md>), [latency](<https://devfeed.tech/tags/latency.md>), [memory](<https://devfeed.tech/tags/memory.md>), [metrics](<https://devfeed.tech/tags/metrics.md>), [network](<https://devfeed.tech/tags/network.md>), [process](<https://devfeed.tech/tags/process.md>), [synchronization](<https://devfeed.tech/tags/synchronization.md>), [systems](<https://devfeed.tech/tags/systems.md>)

## AI overview

This article explains how Square investigated high tail latency affecting a Go application on one machine in an otherwise uniform cluster. Standard system and application metrics appeared normal, so the team used strace to compare hosts and found that fsync() consumed more than twice as much time on the problematic machine. Slightly higher filesystem activity caused fsync() to block and account for nearly all of the observed delay.

## Source excerpt

Debugging Go application latency with strace.