1. A method comprising: determining, by one or more processors, an estimated level of concurrency of a device; determining, by one or more processors, a first average response time, wherein the first average response time is an average of response times of a first set of operations of the device; determining, by one or more processors, a second average response time, wherein the second average response time is an average of response times of a second set of operations of the device, wherein each of the second set of operations is initiated under conditions of minimal interference of the device; determining, by one or more processors, a threshold based on the estimated level of concurrency, wherein the threshold is based on a harmonic number of a value based on a count of service channels of the device; updating, by one or more processors, the estimated level of concurrency based, at least in part, on a ratio of the second average response time to the first average response time; responsive to a determination that the first average response time surpasses the threshold, taking an action on a queue of the device, based at least in part on the updated estimated level of concurrency; wherein determining the threshold further comprises: determining, by one or more processors, a harmonic value of the level of concurrency, including: determining, by one or more processors, a harmonic value of an integer that is greater, by less than one, than the level of concurrency; subtracting, by one or more processors, from the harmonic value of the integer an amount based on a difference between the level of concurrency and the integer; and adjusting, by one or more processors, the harmonic value of the level of concurrency based, at least in part, on a reciprocal of the level of concurrency.