GitLab

Signed-off-by: Tim <tim.wang03@sap.com>

In Prometheus Counters always expose their actual numeric value with a metric name that ends in _total. We should document the base name, as this what appears in the get_metrics() API.
Signed-off-by: CYJiang <86391540+googs1025@users.noreply.github.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: Lifan Shen <lifans@meta.com>

Signed-off-by: Simon Mo <simon.mo@hey.com>
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: atalhens <sneh.lata@nutanix.com>
Co-authored-by: Simon Mo <simon.mo@hey.com>
Co-authored-by: atalhens <sneh.lata@nutanix.com>

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

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

Signed-off-by: Didier Durand <durand.didier@gmail.com>

Signed-off-by: Didier Durand <durand.didier@gmail.com>
Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>
Co-authored-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>

Signed-off-by: Guy Stone <guys@spotify.com>
Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>
Co-authored-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>

Signed-off-by: Chen Zhang <zhangch99@outlook.com>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

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

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

Signed-off-by: windsonsea <haifeng.yao@daocloud.io>

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

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

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

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

Signed-off-by: Chen Zhang <zhangch99@outlook.com>

Signed-off-by: Russell Bryant <rbryant@redhat.com>
Co-authored-by: Cyrus Leung <cyrus.tl.leung@gmail.com>

[Doc] Changed explanation of generation_tokens_total and prompt_tokens_total counter type metrics to avoid confusion (#16784)
Signed-off-by: insukim1994 <insu.kim@moreh.io>

Signed-off-by: yasu52 <tsuguro4649@gmail.com>

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

Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>
Co-authored-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>
Co-authored-by: Cody Yu <hao.yu.cody@gmail.com>