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Wiki / SQLSTATE

08006 — 连接失败（connection_failure）

与服务器的连接在会话中途失败。

英文手册覆盖始于 PostgreSQL 8.1. 来源历史与运行验证各自保留独立版本边界。

当前阅读 PG 18·选择有来源记录的版本

8.18.28.38.49.09.19.29.39.49.59.61011121314151617181920
aliases
未知
class name
Connection Exception
condition name
connection_failure
lang
en
sqlstate
08006

版本定义 PG 18

08006 — 连接失败

速览 {#at-a-glance}

SQLSTATE 08006 是 Class 08 中的 connection_failure。08006 表示已有连接发生故障。固定路径包括 postgres_fdw 的取消/连接丢失处理以及 COPY 失败处理；它们没有一个适用于所有路径的主报文或严重级别，本批也有意不做普通 socket 的伪案例。

含义 {#meaning}

固定源码路径说明了为什么本类没有统一报文。在 postgres_fdw 中，取消请求失败时，在处理已有外部连接的过程中发出 WARNING；这是取消路径的诊断，本身不证明客户端会话已经终止。在 COPY 路径中，带有未完成事务的客户端 EOF 以 ERROR 报告，而较旧的 COPY-to-stdout 路径在输出连接丢失时以 FATAL 报告。严重级别和发生阶段都是含义的一部分，不能把它们合并成“socket 断了”。

ERROR 分支若发生在显式事务中，仍连接着的会话可能进入 INERROR，调用者应先 ROLLBACK 或回到合适的保存点再执行无关 SQL。FATAL 分支会结束后端连接，不存在可以发送 ROLLBACK 的会话。已经读到 EOF 的客户端也可能根本没有 SQLSTATE。这里的证据确认这些源码分支，但没有声称每次普通网络断开都会发出 08006。

分支指引 {#scenarios}

| 固定分支 | 它说明什么 | 首先检查什么 | | --- | --- | --- | | postgres_fdw 取消 WARNING | 已建立的外部连接上，取消请求无法发送或无法读取结果。 | 保留动态 libpq 文本、FDW 操作和本地事务状态；WARNING 本身不说明本地会话已关闭。 | | COPY 客户端 EOF ERROR | 服务器在 COPY 相关连接仍有未完成事务时检测到 EOF。 | 触发该分支的客户端 socket 已经到达 EOF，不能在其上发送 ROLLBACK 或复用；应重新连接并核对 COPY 结果。 | | COPY-to-stdout FATAL | 固定的 10.23 路径在 COPY 期间丢失输出连接，并使用 fatal 级别。 | 丢弃后端连接并核对已经发送或接收的数据；不能执行会话级回滚。 | | 普通客户端 EOF | 对端在固定服务器分支之外消失。 | 结合驱动/socket 和服务器日志；不要仅凭客户端 null SQLSTATE 指定 08006。 |

诊断 {#diagnosis}

关联后端 PID、操作、服务器日志字段和客户端异常。客户端断 socket 可能得到 null SQLSTATE，而服务器端 FDW 或 COPY 路径可能发出带路径特定文本的 08006。决定是否重试前，区分 08001（尚未建立连接）、08007/40003（完成结果不确定）和语句尚未执行成功的普通错误。

要同时检查严重级别和生命周期。WARNING 表示 FDW 取消分支中本地会话可能仍然存活；ERROR 要检查 INERROR 还是 IDLE，必要时恢复事务；FATAL 表示后端已消失。如果客户端在 ErrorResponse 之前只读到 EOF，没有 SQLSTATE 是线路交换丢失的正常证据，不能据此认定 08006。

处理 {#response}

丢弃连接池标记为损坏的连接，核对远端或非幂等操作的结果，并在明确幂等策略后重试完整操作。本页只确认固定源码边界；没有用 RAISE、超时或普通断 socket 冒充实测 08006。

对另一个仍保持连接的 ERROR 情形，应先回滚失败的显式事务（或回滚到围绕该操作有意建立的保存点），再决定能否重试完整操作。这个一般事务规则不能证明 COPY 客户端 EOF socket 可复用：源码分支已经检测到该客户端连接的 EOF。FATAL 或已经丢失的 socket 则要建立新会话，并在任何重放前核对结果。自动提交不会让远端或 COPY 操作自动具备幂等性，它只改变本地事务边界。

报文 {#messages}

固定分支包含以下不同诊断：

  • postgres_fdw 取消路径的 WARNING：could not send cancel request: %s，其中 libpq 错误文本是动态值。
  • 同一 FDW 路径的 WARNING：could not get result of cancel request: %s，返回的连接错误文本是动态值。
  • 固定 10.23 COPY 路径的 FATAL：connection lost during COPY to stdout。
  • 固定 18.6/10.23 COPY 客户端 EOF 路径的 ERROR：unexpected EOF on client connection with an open transaction。

证据将这些变体分开记录；普通客户端断 socket 得到的 null SQLSTATE 不能被提升为 08006。

即使报文都提到连接，ERROR 与 FATAL 也有不同的恢复契约。COPY 客户端 EOF 的 ERROR 分支检测到客户端 socket 已经消失；它不建立可复用 socket，也不提供在该连接上发送 ROLLBACK 的路径。后者属于 COPY-to-stdout 路径，会关闭后端。本批没有自然 08006 运行，因此这些差异来自固定源码路径和文档规定的事务边界，而不是合成的 socket 实验。

代表案例 {#case}

本页没有选定的自然 SQL 运行。结构化证据记录的是源码或定义边界；客户端 RAISE 不能代表服务器机制。

版本 {#versions}

上面的生成事实表记录锁定的目录快照和最早观察到的定义。本页没有选定的自然 SQL 运行；固定的 REL_18_6/REL_10_23 源码边界不能当作实测结果，也不能据此推断所有中间版本的行为。

相关 {#related}

来源 {#sources}

  • src.fdw-connection-failure.18.6 — contrib/postgres_fdw/connection.c at REL_18_6 commit 724edf9bde9d356724ad384a2e196edc3c9f80f7; fixed blob SHA-256 67fc002657f2c7df6d93cbf99c933cbc103907d1857ed77aedbb85099ea4dda0 (source).
  • src.copy-connection-failure.10.23 — src/backend/commands/copy.c at REL_10_23 commit 02991e79f8f58bc208f05dcc8af0c62dbe0a6ea4; fixed blob SHA-256 0edb032be1ce8d8c90efc28e504aa9e298a2cd26cd374c85da6da0e33ed0915c (source).
  • src.copy-client-eof.18.6 — src/backend/commands/copyfromparse.c at REL_18_6 commit 724edf9bde9d356724ad384a2e196edc3c9f80f7; fixed blob SHA-256 bc42754023579cd782a3cb3f144ad2c2c3d3aa46119eb7567fcdb05f2d445571 (source).
  • src.copy-client-eof.10.23 — src/backend/commands/copy.c at REL_10_23 commit 02991e79f8f58bc208f05dcc8af0c62dbe0a6ea4; fixed blob SHA-256 0edb032be1ce8d8c90efc28e504aa9e298a2cd26cd374c85da6da0e33ed0915c (source).
  • src.calls.REL_18_6 / src.calls.REL_10_23 — fixed local call scans, SHA-256 9ee8a0e81d8f0825c5c1ae45583439859a26e602bdd4ce2f2a62aa278867ccbf / 00d16d3eb01b71ccf1b245c8f3102f9d0ec9f36fb02777b8dd1b99fcb263040c; these scans preserve the resolved call context used by the claims.

比较版本

SQLSTATE 证据与已记录的运行版本

cases · source_boundary
{
  "assertions": [],
  "case_id": "source_boundary",
  "cleanup": "Drop the case schema with an owner connection.",
  "has_snippet": false,
  "position": 0,
  "preconditions": [
    "A runner-owned disposable target is provisioned only if a source-boundary smoke run is requested."
  ],
  "repair": "Use the concrete source path or component-specific documentation when it applies.",
  "trigger": "No artificial SQL trigger is executed; this record preserves the fixed source/definition boundary.",
  "versions": [
    "10",
    "18"
  ]
}
claims · identity.class-and-condition
{
  "claim_id": "identity.class-and-condition",
  "limits": "Directory identity does not identify every backend or client path.",
  "method": "Read the fixed errcodes.txt definition and the locked catalogue metadata.",
  "position": 0,
  "runtime": [],
  "sources": [
    "src.errcodes.18.6"
  ],
  "statement": "08006 is the connection_failure condition in Class 08."
}
claims · mechanism.source-boundary
{
  "claim_id": "mechanism.source-boundary",
  "limits": "This is a bounded source claim; this batch has no selected natural 08006 runtime, and it does not claim that an ordinary client socket failure exposes this SQLSTATE.",
  "method": "Trace the fixed REL_18_6 and REL_10_23 source call scans and the recorded source paths.",
  "position": 1,
  "runtime": [],
  "sources": [
    "src.fdw-connection-failure.18.6",
    "src.copy-connection-failure.10.23",
    "src.copy-client-eof.18.6",
    "src.copy-client-eof.10.23"
  ],
  "statement": "The fixed source paths resolve 08006 to distinct established-connection failure branches: postgres_fdw cancel warnings, a COPY-to-stdout FATAL in REL_10_23, and COPY client-EOF ERROR paths in REL_18_6 and REL_10_23. The exact diagnostic and severity depend on where the connection loss is detected."
}
claims · recovery-boundary
{
  "claim_id": "recovery-boundary",
  "limits": "This is a source-backed boundary; the COPY EOF branch says nothing about reusing the already-lost client socket, and this batch selected no natural 08006 runtime or ordinary socket failure.",
  "method": "Combine the COPY client-EOF source branch, recorded source severities, and the official transaction and savepoint recovery contract.",
  "position": 2,
  "runtime": [],
  "sources": [
    "mechanism.source-boundary",
    "doc.transactions.18"
  ],
  "statement": "The fixed 08006 variants have different recovery contracts: the COPY client-EOF ERROR detects that the triggering client socket is already at EOF and therefore does not establish a reusable session for sending ROLLBACK; an independently still-connected ERROR can require rollback or savepoint recovery, while FATAL ends the backend; a client EOF without an ErrorResponse may expose no SQLSTATE."
}
claims · versions.catalogue-boundary
{
  "claim_id": "versions.catalogue-boundary",
  "limits": "Presence in a definition file is not an exact behavioral introduction, and the fixed source paths do not prove every intermediate release or socket failure.",
  "method": "Read the generated facts block and fixed source records; no runtime result is used for this source-only page.",
  "position": 3,
  "runtime": [],
  "sources": [
    "src.errcodes.18.6",
    "src.copy-client-eof.18.6",
    "src.copy-client-eof.10.23"
  ],
  "statement": "The locked catalogue records 08006 in the listed snapshots; this page compares only the fixed REL_18_6 and REL_10_23 source paths and has no selected natural runtime."
}
messages · message.fdw-cancel-send
{
  "limits": "The %s value is the dynamic libpq/cancel error text.",
  "message_id": "message.fdw-cancel-send",
  "path": "",
  "position": 0,
  "raw": {
    "id": "message.fdw-cancel-send",
    "limits": "The %s value is the dynamic libpq/cancel error text.",
    "primary_template": "could not send cancel request: %s",
    "severity_source": "explicit WARNING",
    "sources": [
      "src.fdw-connection-failure.18.6"
    ],
    "sqlstate": "08006"
  },
  "severity": "explicit WARNING",
  "sources": [
    "src.fdw-connection-failure.18.6"
  ],
  "templates": [
    {
      "kind": "primary",
      "literal": "could not send cancel request:",
      "position": 0,
      "role": "",
      "template": "could not send cancel request: %s"
    }
  ]
}
messages · message.fdw-cancel-result
{
  "limits": "The %s value is the dynamic error text returned while reading the cancel result; the fixed source has more than one call site.",
  "message_id": "message.fdw-cancel-result",
  "path": "",
  "position": 1,
  "raw": {
    "id": "message.fdw-cancel-result",
    "limits": "The %s value is the dynamic error text returned while reading the cancel result; the fixed source has more than one call site.",
    "primary_template": "could not get result of cancel request: %s",
    "severity_source": "explicit WARNING",
    "sources": [
      "src.fdw-connection-failure.18.6"
    ],
    "sqlstate": "08006"
  },
  "severity": "explicit WARNING",
  "sources": [
    "src.fdw-connection-failure.18.6"
  ],
  "templates": [
    {
      "kind": "primary",
      "literal": "could not get result of cancel request:",
      "position": 0,
      "role": "",
      "template": "could not get result of cancel request: %s"
    }
  ]
}
messages · message.copy-connection-lost
{
  "limits": "This exact fixed branch is recorded from REL_10_23; the page does not generalize it to every COPY direction or release.",
  "message_id": "message.copy-connection-lost",
  "path": "",
  "position": 2,
  "raw": {
    "id": "message.copy-connection-lost",
    "limits": "This exact fixed branch is recorded from REL_10_23; the page does not generalize it to every COPY direction or release.",
    "primary_template": "connection lost during COPY to stdout",
    "severity_source": "explicit FATAL",
    "sources": [
      "src.copy-connection-failure.10.23"
    ],
    "sqlstate": "08006"
  },
  "severity": "explicit FATAL",
  "sources": [
    "src.copy-connection-failure.10.23"
  ],
  "templates": [
    {
      "kind": "primary",
      "literal": "connection lost during COPY to stdout",
      "position": 0,
      "role": "",
      "template": "connection lost during COPY to stdout"
    }
  ]
}
messages · message.copy-client-eof-open-tx
{
  "limits": "The fixed COPY client-EOF path reports this when an open transaction is present; the source confirms the branch, not a selected natural run in this batch.",
  "message_id": "message.copy-client-eof-open-tx",
  "path": "",
  "position": 3,
  "raw": {
    "id": "message.copy-client-eof-open-tx",
    "limits": "The fixed COPY client-EOF path reports this when an open transaction is present; the source confirms the branch, not a selected natural run in this batch.",
    "primary_template": "unexpected EOF on client connection with an open transaction",
    "severity_source": "explicit ERROR",
    "sources": [
      "src.copy-client-eof.18.6",
      "src.copy-client-eof.10.23"
    ],
    "sqlstate": "08006"
  },
  "severity": "explicit ERROR",
  "sources": [
    "src.copy-client-eof.18.6",
    "src.copy-client-eof.10.23"
  ],
  "templates": [
    {
      "kind": "primary",
      "literal": "unexpected EOF on client connection with an open transaction",
      "position": 0,
      "role": "",
      "template": "unexpected EOF on client connection with an open transaction"
    }
  ]
}
sources · src.errcodes.18.6
{
  "commit": "724edf9bde9d356724ad384a2e196edc3c9f80f7",
  "docs_url": "",
  "kind": "upstream_source",
  "location": "",
  "path": "src/backend/utils/errcodes.txt",
  "position": 0,
  "sha256": "6e8de346643ba84aa3c9c6a73360acfc7b2dfb89162c06c08ce9bf5bcd5bbcba",
  "source_id": "src.errcodes.18.6",
  "tag": "REL_18_6",
  "url": "https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/src/backend/utils/errcodes.txt"
}
sources · src.calls.REL_18_6
{
  "commit": "",
  "docs_url": "",
  "kind": "local_artifact",
  "location": "",
  "path": "raw/calls/REL_18_6.jsonl",
  "position": 1,
  "sha256": "9ee8a0e81d8f0825c5c1ae45583439859a26e602bdd4ce2f2a62aa278867ccbf",
  "source_id": "src.calls.REL_18_6",
  "tag": "REL_18_6",
  "url": ""
}
sources · src.calls.REL_10_23
{
  "commit": "",
  "docs_url": "",
  "kind": "local_artifact",
  "location": "",
  "path": "raw/calls/REL_10_23.jsonl",
  "position": 2,
  "sha256": "00d16d3eb01b71ccf1b245c8f3102f9d0ec9f36fb02777b8dd1b99fcb263040c",
  "source_id": "src.calls.REL_10_23",
  "tag": "REL_10_23",
  "url": ""
}
sources · src.fdw-connection-failure.18.6
{
  "commit": "724edf9bde9d356724ad384a2e196edc3c9f80f7",
  "docs_url": "",
  "kind": "upstream_source",
  "location": "",
  "path": "contrib/postgres_fdw/connection.c",
  "position": 3,
  "sha256": "67fc002657f2c7df6d93cbf99c933cbc103907d1857ed77aedbb85099ea4dda0",
  "source_id": "src.fdw-connection-failure.18.6",
  "tag": "REL_18_6",
  "url": "https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/contrib/postgres_fdw/connection.c#L1462-L1464"
}
sources · src.copy-connection-failure.10.23
{
  "commit": "02991e79f8f58bc208f05dcc8af0c62dbe0a6ea4",
  "docs_url": "",
  "kind": "upstream_source",
  "location": "",
  "path": "src/backend/commands/copy.c",
  "position": 4,
  "sha256": "0edb032be1ce8d8c90efc28e504aa9e298a2cd26cd374c85da6da0e33ed0915c",
  "source_id": "src.copy-connection-failure.10.23",
  "tag": "REL_10_23",
  "url": "https://github.com/postgres/postgres/blob/02991e79f8f58bc208f05dcc8af0c62dbe0a6ea4/src/backend/commands/copy.c#L525-L527"
}
sources · manifest.08006
{
  "commit": "",
  "docs_url": "",
  "kind": "local_artifact",
  "location": "",
  "path": "verify/cases/08006/cases.json",
  "position": 5,
  "sha256": "205dd83742e554dc0ceb466ed9acd023f538785306e2a2b29a7ec3842a8f50af",
  "source_id": "manifest.08006",
  "tag": "workspace",
  "url": "verify/cases/08006/cases.json"
}
sources · src.copy-client-eof.18.6
{
  "commit": "724edf9bde9d356724ad384a2e196edc3c9f80f7",
  "docs_url": "",
  "kind": "upstream_source",
  "location": "",
  "path": "src/backend/commands/copyfromparse.c",
  "position": 6,
  "sha256": "bc42754023579cd782a3cb3f144ad2c2c3d3aa46119eb7567fcdb05f2d445571",
  "source_id": "src.copy-client-eof.18.6",
  "tag": "REL_18_6",
  "url": "https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/src/backend/commands/copyfromparse.c#L276-L303"
}
sources · src.copy-client-eof.10.23
{
  "commit": "02991e79f8f58bc208f05dcc8af0c62dbe0a6ea4",
  "docs_url": "",
  "kind": "upstream_source",
  "location": "",
  "path": "src/backend/commands/copy.c",
  "position": 7,
  "sha256": "0edb032be1ce8d8c90efc28e504aa9e298a2cd26cd374c85da6da0e33ed0915c",
  "source_id": "src.copy-client-eof.10.23",
  "tag": "REL_10_23",
  "url": "https://github.com/postgres/postgres/blob/02991e79f8f58bc208f05dcc8af0c62dbe0a6ea4/src/backend/commands/copy.c#L587-L614"
}
sources · doc.transactions.18
{
  "commit": "724edf9bde9d356724ad384a2e196edc3c9f80f7",
  "docs_url": "",
  "kind": "upstream_source",
  "location": "",
  "path": "doc/src/sgml/xact.sgml",
  "position": 8,
  "sha256": "b48fbe8bd02ce3d1181a350c88c8baa6e11c73edc90a936e77b180daef328c5c",
  "source_id": "doc.transactions.18",
  "tag": "PG18-docs",
  "url": "https://www.postgresql.org/docs/18/tutorial-transactions.html"
}

来源引用

完整定义与证据 JSON

定义来源

center · PostgreSQL 18 · english-manuals:27579a490920a8273428e87cff8d866374221184a614a8ca900493f2805c08e1

正文语言: zh-Hans · english-manuals:27579a490920a8273428e87cff8d866374221184a614a8ca900493f2805c08e1