# Client: GssOpenServer

> 建立 GSSAPI 会话时，等待从客户端读取数据。
---

<div class="event-kicker">PostgreSQL 等待事件档案</div>
<div class="event-identity">
  <span>类别<strong>Client</strong></span>
  <span>事件<strong><code>GssOpenServer</code></strong></span>
  <span>版本<strong>PG 17-18</strong></span>
  <span>证据<strong>4 个源码位置</strong></span>
</div>

## 官方描述译文 {#official-description}

建立 GSSAPI 会话时，等待从客户端读取数据。

| PG 13 | PG 14 | PG 15 | PG 16 | PG 17 | PG 18 |
| :---: | :---: | :---: | :---: | :---: | :---: |
| — | — | — | — | ✓ | ✓ |

**历史名称：**`Client/GSSOpenServer` (PG 13-16)

## 触发机制 {#mechanism}

`WAIT_EVENT_GSS_OPEN_SERVER` 位于 `src/backend/libpq/be-secure-gssapi.c:461`，是经 grep 核验的报告路径。公共身份/资源映射位于 `src/backend/utils/activity/wait_event.c:277`。探针覆盖的操作是：建立 GSSAPI 会话时，等待从客户端读取数据。前端协议路径在套接字、TLS/GSS 或复制客户端操作即将阻塞前报告 GssOpenServer；PostgreSQL 正在等待远端或网络推进。

## 正常还是麻烦？ {#normal-vs-trouble}

- <span class="severity-normal">**正常:**</span> 空闲状态的 ClientRead 通常只是连接池存量。
- <span class="severity-watch">**需要调查:**</span> 活动写入、握手、很老的 idle in transaction、连接耗尽或复制客户端停滞时需要调查。

## 诊断 SQL {#diagnostic-sql}

```sql {title="正在等待 Client/GssOpenServer 的会话"}
SELECT pid, backend_type, usename, datname, application_name,
       state, now() - query_start AS query_age,
       now() - xact_start AS xact_age,
       wait_event_type, wait_event,
       pg_blocking_pids(pid) AS blocking_pids,
       left(query, 160) AS query
FROM pg_stat_activity
WHERE wait_event_type = 'Client'
  AND wait_event = 'GssOpenServer'
ORDER BY query_age DESC NULLS LAST;
```

```sql {title="当前 Client 等待分布"}
SELECT wait_event, count(*) AS waiting_sessions,
       count(*) FILTER (WHERE state = 'active') AS active_waiters,
       max(now() - query_start) AS oldest_query
FROM pg_stat_activity
WHERE wait_event_type = 'Client'
GROUP BY wait_event
ORDER BY waiting_sessions DESC, wait_event;
```

```sql {title="这些会话的锁与关系上下文"}
SELECT a.pid, l.locktype, l.mode, l.granted, l.fastpath,
       d.datname, n.nspname, c.relname,
       l.page, l.tuple, l.virtualxid, l.transactionid,
       l.classid, l.objid, l.objsubid
FROM pg_stat_activity AS a
LEFT JOIN pg_locks AS l ON l.pid = a.pid
LEFT JOIN pg_database AS d ON d.oid = l.database
LEFT JOIN pg_class AS c
  ON c.oid = l.relation
 AND l.database = (
       SELECT oid FROM pg_database WHERE datname = current_database()
     )
LEFT JOIN pg_namespace AS n ON n.oid = c.relnamespace
WHERE a.wait_event_type = 'Client'
  AND a.wait_event = 'GssOpenServer'
ORDER BY a.pid, l.granted, l.locktype, l.mode;
```

## 处置建议 {#response}

1. 先看 state 与事务年龄，再决定它是否算负载。
2. 关联负责的应用、连接池与网络路径。
3. 修复消费者背压或连接池策略，不要反复终止连接。

## 源码证据 {#source}

- [PostgreSQL 16.15 · src/backend/libpq/be-secure-gssapi.c:461](https://github.com/postgres/postgres/blob/REL_16_15/src/backend/libpq/be-secure-gssapi.c#L461) — `WAIT_EVENT_GSS_OPEN_SERVER`
- [PostgreSQL 16.15 · src/backend/utils/activity/wait_event.c:277](https://github.com/postgres/postgres/blob/REL_16_15/src/backend/utils/activity/wait_event.c#L277) — `GSSOpenServer`
- [PostgreSQL 18.6 · src/backend/libpq/be-secure-gssapi.c:462](https://github.com/postgres/postgres/blob/REL_18_6/src/backend/libpq/be-secure-gssapi.c#L462) — `WAIT_EVENT_GSS_OPEN_SERVER`
- [PostgreSQL 18.6 · src/backend/utils/activity/wait_event_names.txt:87](https://github.com/postgres/postgres/blob/REL_18_6/src/backend/utils/activity/wait_event_names.txt#L87) — `GSS_OPEN_SERVER`

## 关联控制项与信号 {#related}

- **GUC:** [[guc:max_connections]](/zh/guc/max-connections/) · [[guc:idle_in_transaction_session_timeout]](/zh/guc/idle-in-transaction-session-timeout/)
- **指标:** [[metric:waiting_sessions]](/zh/metric/waiting-sessions/) · [[metric:wait_event_share]](/zh/metric/wait-event-share/) · [[metric:active_backends]](/zh/metric/active-backends/)

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反链：

- [Client](/zh/client/)