Previous versions of the runner would truncate inputs to the context
window before beginning processing. The main processing loop relied
on this behavior if the context needed to be shifted later (due to
token generation). If truncation did not occur then invariants
would be broken, causing crashes or infinite loops.
Later versions attempted to fix these bugs and make the logic less
subtle so that all inputs could be handled. Truncation was removed
to make things consistent.
However, truncation is much faster than processing and shifting, so
removing it caused performance problems when the input vastly exceeded
the context size. This restores the input truncation as a performance
optimization while keeping the more robust processing logic.
Fixes#7762
We need to track which tokens are in the cache ourselves. We currently
add tokens to the cache tracker when we add them to batch but they are
not actually in the cache until we call Decode. This can cause
confusion when we are shifting the cache.
Avoids "could not find a KV slot for the batch" issues.
Bug #7545
We try to recover from errors by dropping the tokens that caused the
problem and re-trying. However, dropping the tokens is not correct
and continuing often leads to infinite loops. To avoid, this we
end the sequence if such a condition is detected, which is also
surprising.
At this point, it is better to just report the error. This will make
it easier to find problems and the alternatives are perhaps even more
surprising to users.
This is not a very satisfactory solution either - we should isolate
the error and return it to the user without killing the whole process.
However, this is an incremental step and consistent with most other
failures (which either manifest as abort() or panic).
Fragmentation of the KV cache can occur due to cache shifting or
different sequences getting processed. Decode uses a heuristic to
decide if it should defrag. However, this heuristic isn't 100%
accurate, so decoding can sometimes fail by surprise.
For these cases, if decode indicates that there is no KV cache space,
we should defrag and then try again.
Many model crashes are masked behind "An existing connection was forcibly closed by the remote host"
This captures that common error message and wires in any detected errors from the log.
This also adds the deepseek context shift error to the known errors we capture.
This change allows for mixed-case model names to be pushed, pulled,
copied, and created, which was previously disallowed because the Ollama
registry was backed by a Docker registry that enforced a naming
convention that disallowed mixed-case names, which is no longer the
case.
This does not break existing, intended, behaviors.
Also, make TestCase test a story of creating, updating, pulling, and
copying a model with case variations, ensuring the model's manifest is
updated correctly, and not duplicated across different files with
different case variations.
This is a partial revert of 8a35bb92
"runner.go: Increase survivability of main processing loop", removing
the panic handler.
Although we want to avoid errors taking down the runner, we also
should make the user aware of problems when they happen. In the
future, we can restructure things so both parts are true.
Currently, if an error occurs during the prep stages (such as
tokenizing) of a single request, it will only affect that request.
However, if an error happens during decoding, it can take down the
entire runner.
Instead, it's better to drop the tokens that triggered the error and try to
keep going. However, we also need to stop when we run out of tokens,
otherwise, this just causes an infinite loop. This is likely the cause
of at least some of the hanging issues that have been reported.
Bug #7573
It's possible to get prompts that consist entirely of whitespace -
this is most likely to happen when generating embeddings. Currently,
we will trim this away, leaving an empty prompt, which will then
generate an error.
Generating embeddings from whitespace should not trigger an error,
as this may break pipelines. It's better to just leave the whitespace
in place and process what we are given. This is consistent with
past versions of Ollama.
Bug #7578
NUM_PARALEL is currently enforced by the Ollama server process - it
will only issue requests to the runner if the maximum number of
concurrent requests has not been exceeded. Although this should
be sufficient, it is good for the runner to protect its own data
structures. Currently, if too many requests get through to the
runner, they will just get stuck and never return.
This may help with reports of Ollama hanging, though it is unclear
how it would actually occur.
Bug #7573
Docker uses the container filesystem for name resolution, so we can't guide users
to use the name of the host group. Instead they must specify the numeric ID.
The structure of the accounting for KV cache shifting was carried
over from the old runner but it now doesn't feel natural with the new
runner. There are a number of invariants that should hold true but
are difficult to reason about. There is at least one bug report
that would imply that the invariants are not holding.
This reduces the number of implicit assumptions and is more forgiving
of unexpected situations. It also improves behavior around which input
tokens are kept when truncation occurs.
Bug #7545
