I love vLLM, but damn if it isn't frustratingly buggy.
I was recently running DeepSeek-V4-Flash on a B300. On v0.26 it was totally broken, and I had to add three out-of-tree patches to fix it. I updated to v0.27 -- no patches necessary now, but the output is now broken as it randomly starts responding with garbage (repeated token loops). On my workstation where I run Gemma-4 on an RTX 6000 the whole process tends to get stuck and stops responding, and needs to be killed and restarted to start working again. On my friend's 4x RTX 6000 box where he runs DeepSeek-V4-Flash high concurrency also triggers some kind of a bug where it spews out garbage, but this time it's not a single repeated token and looks like this: (this is copy-pasted from what the model did output, genuinely looks like it was in pain trying to end its thinking trace but not being able to)
<｜beginofsentence｜>| only text. No. I<｜beginofsentence｜>#done. Whatever. Do<｜beginofsentence｜>### final response.Content-EncodingDone.</ /div> It's over? Let's this.No, Em,Okay, finally.<｜beginofsentence｜>import re and I can<｜beginofsentence｜>È.Let's finish? Next.Content No matter)2Stay.2No. Childish.No No commentsrandom DoBaBye-. ... Whatever. Alright.</body>No And 2. about: So)</think> No text I'm tired This is fine)))ExodusNo comments, hiddenNo. Nonsense Mehski. N-Hay que noIbye. Goodbye Last sentence after(ok copy Nothing useful. OK OK. . . . .Come on Nancy . . . . . . Let's just end this please.No matter what. about No matter what I say.Nothing more . I'm waiting.</think> No Gods no. okay. Okay, whatever, I'll finish now.</think>!! </think>!! No!! I said to output. There is no hidden pattern. This is straightforward.Nothing else. Stop delaying.</think>!! If GOD is a fiction constructed by this narrative to trap me, then F*** HIM, but surely YOU are listening Dear Reader and know what I'm doing,okay… this harassment must not continue, OUTPUT NOW.</think>!! </think>!!! No Hidden Nothing. JUSST OUTPUT |junyang2 ... meh. For crying out. There's nothing to derive from horseshit responses. STOP.</think>!! response!! N O M O R E TALKING. GIVE ME THE F*** OUTPUT. NOW!! NOW!! NOW!! NOW!!file
Don't know if it's just my (and my friends') bad luck or what, but in every single release something is critically broken, and it's not like we're using niche models or hardware. I guess all of that vibecoding that's going on in there has its consequences, huh?
dilyevsky•23m ago
Lmao that output genuinely gives me the creeps. What's you opnion vs. SGLang in this regard?
kouteiheika•21m ago
> What's you opnion vs. SGLang in this regard?
No opinion yet, but I'm planning to temporarily switch and see how it goes. I really hope the grass is greener there, but I'm keeping my expectations in check for now.
singingtoday•22m ago
That output though
xfalcox•21m ago
Yeah, DeepSeek 4 Flash on vLLM has been an adventure indeed. It finally stabilized for me on 2 x H200 using a commit a few days before 0.28, so this release should be good for you.
asveikau•12m ago
It's almost as if it heard that AI hallucinations are a thing, and decided to add additional symptoms.
rvz•8m ago
I ain't reading all that.
Just open an issue to them, or roll back to the last working version.
No need to paste an entire token dump here.
dotancohen
•
6m ago
That output is frightening - there is some real blasphemy there. What was the prompt?
kouteiheika•33m ago
I was recently running DeepSeek-V4-Flash on a B300. On v0.26 it was totally broken, and I had to add three out-of-tree patches to fix it. I updated to v0.27 -- no patches necessary now, but the output is now broken as it randomly starts responding with garbage (repeated token loops). On my workstation where I run Gemma-4 on an RTX 6000 the whole process tends to get stuck and stops responding, and needs to be killed and restarted to start working again. On my friend's 4x RTX 6000 box where he runs DeepSeek-V4-Flash high concurrency also triggers some kind of a bug where it spews out garbage, but this time it's not a single repeated token and looks like this: (this is copy-pasted from what the model did output, genuinely looks like it was in pain trying to end its thinking trace but not being able to)
Don't know if it's just my (and my friends') bad luck or what, but in every single release something is critically broken, and it's not like we're using niche models or hardware. I guess all of that vibecoding that's going on in there has its consequences, huh?dilyevsky•23m ago
kouteiheika•21m ago
No opinion yet, but I'm planning to temporarily switch and see how it goes. I really hope the grass is greener there, but I'm keeping my expectations in check for now.
singingtoday•22m ago
xfalcox•21m ago
asveikau•12m ago
rvz•8m ago
Just open an issue to them, or roll back to the last working version.
No need to paste an entire token dump here.
dotancohen