服务器名称哈希桶大小配置值过小
nginx: [emerg] the "server_names_hash_bucket_size" directive value is too small
ID: nginx/name-too-long-buffer-overflow
版本兼容性
| 版本 | 状态 | 引入 | 弃用 | 备注 |
|---|---|---|---|---|
| nginx/1.18.0 | active | — | — | — |
| nginx/1.20.0 | active | — | — | — |
| nginx/1.24.0 | active | — | — | — |
| nginx/1.26.0 | active | — | — | — |
根因分析
配置的 server_names_hash_bucket_size 不足以容纳定义的服务器名称长度，导致哈希表桶溢出。
English
The configured server_names_hash_bucket_size is insufficient for the length of server names defined, causing hash table bucket overflow.
官方文档
https://nginx.org/en/docs/http/ngx_http_core_module.html#server_names_hash_bucket_size解决方案
-
在 http 块中将 server_names_hash_bucket_size 增加到至少 128：`http { server_names_hash_bucket_size 128; ... }` -
如果错误仍然存在，将值加倍（例如 256）并重新加载：`http { server_names_hash_bucket_size 256; }` -
缩短长服务器名称或使用通配符（例如 *.example.com 替代 very-long-subdomain.example.com）以减少名称长度。
无效尝试
常见但无效的做法:
-
70% 失败
server_names_hash_max_size sets the total hash size, while bucket size controls per-bucket alignment; max_size without increasing bucket_size still causes overflow for long names.
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50% 失败
The error is configuration-specific; removing names only avoids the symptom, not the root cause, and names must be re-added eventually.
-
60% 失败
The value must be a power of two (e.g., 32, 64, 128, 256) to align with CPU cache lines; non-power-of-two values are ignored or cause other errors.