![]() Milliseconds (or 115 microseconds), which is a good news, however keep in mind In the above example, the intrinsic latency of the system is just 0.115 In this special mode redis-cli does not connect to a Redis server at all: it will just try to measure the largest time the kernel does not provide CPU time to run to the redis-cli process itself. ![]() Note: redis-cli in this special case needs to run in the server where you run or plan to run Redis, not in the client. Intensive and will likely saturate a single core in your system. To perform a few runs at different times. 100 seconds is usually appropriate, however you may want The more time we run the test, the more likely we'll be able to spot Note: the argument 100 is the number of seconds the test will be executed. Under Linux 3.11.0 running on an entry level server. We call this kind of latency intrinsic latency, and redis-cli startingįrom Redis version 2.8.7 is able to measure it. Latency that is better than the latency that every process running in yourĮnvironment will experience because of the kernel or hypervisor implementation It is the baseline, or in other words, you won't be able to achieve a Redis While this latency can't be removed it is important to study it because You run Redis, that is the latency provided by your operating system kernelĪnd, if you are using virtualization, by the hypervisor you are using. There is a kind of latency that is inherently part of the environment where It simpler to understand the source of latency in your Redis system, it is stillĪdvised that you read this documentation extensively to better understand While the latency monitoring sampling and reporting capabilities will make Please refer to the Latency monitor documentation. This documentation much simpler, so we suggest enabling latency monitoringĪSAP. This makes debugging of the problems illustrated in Since Redis 2.8.13, Redis provides latency monitoring capabilities thatĪre able to sample different execution paths to understand where the Using the internal Redis latency monitoring subsystem Latency of a Redis server in milliseconds, just try: redis-cli -latency -h `host` -p `port` However redis-cli can be used to measure the It in the context of your application, or maybe your latency problem is veryĮvident even macroscopically. If you are experiencing latency problems, you probably know how to measure Here you have a vast spectrum of tradeoffs depending on the save triggers you configure.Īnd now for people with 15 minutes to spend, the details. Fsyncing is up to the kernel in this setup, even less disk pressure and risk of latency spikes.
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