I have been running a couple of blast searches and I am very suprised and somewhat frustrated by the huge variability in job completion time. The specifics of my blast search are as follows:
- Running blast using webbrowser (chrome) via ncbi
- 19 nucleotide query
- database: WGS of one particular sequencing project/bacterial strain (so database is VERY small, in total approx 4.5 MB divided over 60 contigs)
- parameters are mostly untouched and are automatically optimized for short queries by blast
In one instance, I started the job more than an hour ago and it is still not done. Knowing from experience that this previously hasn't taken that much time, I started a new job in a different browser tab with exactly the same sequence, database and parameters, and now it finished within 20 seconds. What on earth is happening here?