GitLab

Signed-off-by: Ziliang Peng <ziliang@character.ai>

Signed-off-by: Nick Hill <nhill@redhat.com>

Signed-off-by: Yong Hoon Shin <yhshin@meta.com>

Introduces three new Prometheus histograms for fine-grained observability of KV cache residency behavior:

vllm:kv_block_lifetime_seconds — total lifetime from allocation to free
vllm:kv_block_idle_before_evict_seconds — idle duration before eviction
vllm:kv_block_reuse_gap_seconds — time between consecutive reuses of the same block

These metrics help operators analyze KV cache efficiency, reuse patterns, and eviction timing beyond simple utilization rates.

Implementation uses monotonic timestamps for accuracy, 1% sampling for minimal overhead (~48 bytes/block), and is fully thread-safe with zero runtime cost when disabled.

Two new runtime flags are introduced:

--kv-cache-metrics – enable KV cache residency metrics
--kv-cache-metrics-sample – control sampling ratio (default: 0.01)
Signed-off-by: Shivam <shivamprasad91@gmail.com>

Signed-off-by: DarkLight1337 <tlleungac@connect.ust.hk>

Signed-off-by: Mark McLoughlin <markmc@redhat.com>

Signed-off-by: wangxiyuan <wangxiyuan1007@gmail.com>

The `vllm:kv_cache_usage_perc` Gauge metric is missing `multiprocess_mode="mostrecent"` and ends up returning

```
vllm:kv_cache_usage_perc{engine="0",model_name="Qwen/Qwen3-VL-8B-Instruct",pid="277"} 0.0
vllm:kv_cache_usage_perc{engine="0",model_name="Qwen/Qwen3-VL-8B-Instruct",pid="275"} 0.0
vllm:kv_cache_usage_perc{engine="0",model_name="Qwen/Qwen3-VL-8B-Instruct",pid="273"} 0.6530455880475035
...
```

The deprecated `vllm:gpu_cache_usage_perc` Gauge metric has `multiprocess_mode="mostrecent"`.
Signed-off-by: Jae-Won Chung <jwnchung@umich.edu>

Add tracking and periodic logging for the number of preempted requests in the
metrics logger. This helps monitor system behavior under load.
Signed-off-by: Yining Liu <610lyn@gmail.com>

Signed-off-by: Mark McLoughlin <markmc@redhat.com>

Signed-off-by: atalhens <sneh.lata@nutanix.com>

Signed-off-by: Mark McLoughlin <markmc@redhat.com>

Signed-off-by: SumanthRH <sumanthrh99@gmail.com>

Signed-off-by: NickLucche <nlucches@redhat.com>
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Co-authored-by: Mark McLoughlin <markmc@redhat.com>

Signed-off-by: Braulio Dumba <Braulio.Dumba@ibm.com>

Signed-off-by: yewentao256 <zhyanwentao@126.com>

Signed-off-by: tovam <tovam@pliops.com>

Signed-off-by: tovam <tovam@pliops.com>

Signed-off-by: Lu Fang <fanglu@fb.com>

Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>

Signed-off-by: Mark McLoughlin <markmc@redhat.com>

Signed-off-by: DarkLight1337 <tlleungac@connect.ust.hk>

Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>

Signed-off-by: NickLucche <nlucches@redhat.com>

Co-authored-by: Ye (Charlotte) Qi <yeq@meta.com>
Signed-off-by: Zhuohan Li <zhuohan123@gmail.com>

Signed-off-by: baxingpiaochong <771405853@qq.com>

Signed-off-by: NickLucche <nlucches@redhat.com>

Signed-off-by: Mark McLoughlin <markmc@redhat.com>

Signed-off-by: wuhang <wuhang6@huawei.com>
Co-authored-by: Robert Shaw <114415538+robertgshaw2-redhat@users.noreply.github.com>

Signed-off-by: chaunceyjiang <chaunceyjiang@gmail.com>
Co-authored-by: Nick Hill <nhill@redhat.com>

Signed-off-by: Seiji Eicher <seiji@anyscale.com>
Signed-off-by: Seiji Eicher <58963096+eicherseiji@users.noreply.github.com>
Co-authored-by: Nick Hill <nhill@redhat.com>

Signed-off-by: Mark McLoughlin <markmc@redhat.com>

Signed-off-by: zitian.zhao <zitian.zhao@tencentmusic.com>

Signed-off-by: Robert Shaw <robshaw@redhat.com>
Co-authored-by: Robert Shaw <robshaw@redhat.com>

Signed-off-by: Max de Bayser <mbayser@br.ibm.com>
Signed-off-by: Max de Bayser <maxdebayser@gmail.com>
Signed-off-by: 22quinn <33176974+22quinn@users.noreply.github.com>
Co-authored-by: 22quinn <33176974+22quinn@users.noreply.github.com>

Signed-off-by: Saheli Bhattacharjee <saheli@krai.ai>

Signed-off-by: simon-mo <simon.mo@hey.com>

Signed-off-by: Mark McLoughlin <markmc@redhat.com>

Signed-off-by: Seiji Eicher <seiji@anyscale.com>