I try to install ranger-2.0.0 on my cluster, however, I try to create a new service in Ranger WebUI, when I click the Add button, I keep stuck in the Please waiting state for a long time, and finally get an error that createService failed.
I try to debug through the source code, and found that it stuck on generateBase64EncodedIV() in PasswordUtils.java. It uses SecureRandom.getInstanceStrong() to get the random string. We can find a lot of information showing that this function often blocks and is very slow. SecureRandom.getInstanceStrong() uses /dev/random, and /dev/random blocks the thread if there isn't enough randomness available, but /dev/urandom will never block.
SecureRandom.getInstanceStrong() is equivalent to SecureRandom.getInstance("NativePRNGBlocking"), so we can use /dev/urandom by replacing SecureRandom.getInstanceStrong().nextBytes(iv) with SecureRandom.getInstance("NativePRNGNonBlocking").nextBytes(iv) which will not be blocked, or we can use new SecureRandom().nextBytes(iv). /dev/random and /dev/urandom use the same pool of randomness under the hood, and they are equally secure.