Meta additionally has some internal software called Zelos, which is the zookeeper api but implemented on delos[0], though you didn't hear it from me [0] https:

Meta additionally has some internal software called Zelos, which is the zookeeper api but implemented on delos[0], though you didn't hear it from me [0] https://www.usenix.org/system/files/osdi20-balakrishnan.pdf https://www.usenix.org/system/files/osdi20-balakrishnan.pdf