[Core] Buffered logs lost sometimes

[Robert Nishihara]

What happened + What you expected to happen

When running in IPython, some print statements are sometimes suppressed. We buffer them under the hood and deduplicate them (ignoring numerical values), but then they never seem to get printed.

In [1]: import time

In [2]: import ray

In [3]: @ray.remote
   ...: def f(i):
   ...:     print(i)
   ...:

In [4]: [f.remote(i) for i in range(10)]
2024-05-10 18:01:35,772	INFO worker.py:1740 -- Started a local Ray instance. View the dashboard at http://127.0.0.1:8266
Out[4]:
[ObjectRef(c8ef45ccd0112571ffffffffffffffffffffffff0100000001000000),
 ObjectRef(16310a0f0a45af5cffffffffffffffffffffffff0100000001000000),
 ObjectRef(c2668a65bda616c1ffffffffffffffffffffffff0100000001000000),
 ObjectRef(32d950ec0ccf9d2affffffffffffffffffffffff0100000001000000),
 ObjectRef(e0dc174c83599034ffffffffffffffffffffffff0100000001000000),
 ObjectRef(f4402ec78d3a2607ffffffffffffffffffffffff0100000001000000),
 ObjectRef(f91b78d7db9a6593ffffffffffffffffffffffff0100000001000000),
 ObjectRef(82891771158d68c1ffffffffffffffffffffffff0100000001000000),
 ObjectRef(8849b62d89cb30f9ffffffffffffffffffffffff0100000001000000),
 ObjectRef(80e22aed7718a125ffffffffffffffffffffffff0100000001000000)]

(f pid=31071) 7
In [5]: time.sleep(1)

In [6]: time.sleep(5)

In [7]: ray.put(1)
Out[7]: ObjectRef(00ffffffffffffffffffffffffffffffffffffff0100000001e1f505)

In [8]:

In [8]: f.remote(0)
Out[8]: ObjectRef(359ec6ce30d3ca2dffffffffffffffffffffffff0100000001000000)

(f pid=31068) 0
In [9]:

In [9]:
Do you really want to exit ([y]/n)?

Versions / Dependencies

Python 3.11.4
ray, version 2.21.0
macOS 13.5

Reproduction script

See above

Issue Severity

None