Span
编辑Span编辑
Span 包含有关特定代码路径执行的信息。它们测量活动的开始和结束时间，并且可以与其他 span 具有父子关系。
代理会自动检测各种库，以从您的应用程序中捕获这些 span，但您也可以使用代理 API 对特定代码路径进行自定义检测。
除此之外，span 还可以包含
- 一个
transaction.id属性，用于引用其父 事务。 - 一个
parent.id属性，用于引用其父 span 或事务。 - 其开始时间和持续时间。
- 一个
name、type、subtype和action- 有关 span 名称模式和 APM 代理示例，请参阅 span 名称/类型对齐 表格。此外，一些 APM 代理会根据公共 span 类型/子类型规范 进行测试。 - 一个可选的
stack trace。堆栈跟踪由堆栈帧组成，这些堆栈帧表示调用堆栈上的函数调用。它们包括函数名称、文件名和路径、行号等属性。
大多数代理将关键字字段（如 span.id）限制为 1024 个字符，将非关键字字段（如 span.start.us）限制为 10,000 个字符。
丢弃的 span编辑
出于性能原因，APM 代理可以选择有目的地对 span 进行采样或省略。这在防止边缘情况（例如，具有超过 100 个 span 的长时间运行事务）方面非常有用，否则这些情况会使代理和 APM 服务器过载。发生这种情况时，APM 应用程序将显示丢弃的 span 数。
要配置每个事务记录的 span 数，请参阅相关的代理文档
- Android：*尚不支持*
- Go：
ELASTIC_APM_TRANSACTION_MAX_SPANS - iOS：*尚不支持*
- Java：
transaction_max_spans - .NET：
TransactionMaxSpans - Node.js：
transactionMaxSpans - PHP：
transaction_max_spans - Python：
transaction_max_spans - Ruby：
transaction_max_spans
缺少的 span编辑
代理将 span 与其事务分开流式传输到 APM 服务器。因此，不可预见的错误可能会导致 span 丢失。代理知道一个事务应该有多少个 span；如果预期 span 数与 APM 服务器接收到的 span 数不相等，APM 应用程序将计算差值并显示一条消息。
数据流编辑
Span 与事务一起存储在以下数据流中
- 应用程序跟踪：
traces-apm-<namespace> - RUM 和 iOS 代理应用程序跟踪：
traces-apm.rum-<namespace>
有关详细信息，请参阅 数据流。
示例 span 文档编辑
此示例显示了在 Elasticsearch 中索引时 span 文档的外观。
展开 Elasticsearch 文档
[
{
"@timestamp": "2017-05-30T18:53:27.154Z",
"agent": {
"name": "elastic-node",
"version": "3.14.0"
},
"ecs": {
"version": "1.12.0"
},
"event": {
"outcome": "unknown"
},
"http": {
"request": {
"method": "GET"
},
"response": {
"status_code": 200
}
},
"labels": {
"span_tag": "something"
},
"observer": {
"hostname": "ix.lan",
"type": "apm-server",
"version": "8.0.0"
},
"parent": {
"id": "945254c567a5417e"
},
"processor": {
"event": "span",
"name": "transaction"
},
"service": {
"environment": "staging",
"name": "1234_service-12a3"
},
"span": {
"action": "query",
"db": {
"instance": "customers",
"statement": "SELECT * FROM product_types WHERE user_id=?",
"type": "sql",
"user": {
"name": "readonly_user"
}
},
"duration": {
"us": 3781
},
"http": {
"method": "GET",
"response": {
"status_code": 200
}
},
"http.url.original": "https://127.0.0.1:8000",
"id": "0aaaaaaaaaaaaaaa",
"name": "SELECT FROM product_types",
"stacktrace": [
{
"abs_path": "net.js",
"context": {
"post": [
" ins.currentTransaction = prev",
" return result",
"}"
],
"pre": [
" var trans = this.currentTransaction",
""
]
},
"exclude_from_grouping": false,
"filename": "net.js",
"function": "onread",
"library_frame": true,
"line": {
"column": 4,
"context": "line3",
"number": 547
},
"module": "some module",
"vars": {
"key": "value"
}
},
{
"exclude_from_grouping": false,
"filename": "my2file.js",
"line": {
"number": 10
}
}
],
"start": {
"us": 2830
},
"subtype": "postgresql",
"sync": false,
"type": "db"
},
"timestamp": {
"us": 1496170407154000
},
"trace": {
"id": "945254c567a5417eaaaaaaaaaaaaaaaa"
},
"transaction": {
"id": "945254c567a5417e"
},
"url": {
"original": "https://127.0.0.1:8000"
}
},
{
"@timestamp": "2017-05-30T18:53:42.281Z",
"agent": {
"name": "js-base",
"version": "1.3"
},
"destination": {
"address": "0:0::0:1",
"ip": "0:0::0:1",
"port": 5432
},
"ecs": {
"version": "1.12.0"
},
"event": {
"outcome": "unknown"
},
"observer": {
"ephemeral_id": "2f13d8fa-83cd-4356-8123-aabfb47a1808",
"hostname": "goat",
"id": "17ad47dd-5671-4c89-979f-ef4533565ba2",
"type": "apm-server",
"version": "8.0.0"
},
"parent": {
"id": "85925e55b43f4342"
},
"processor": {
"event": "span",
"name": "transaction"
},
"service": {
"environment": "staging",
"name": "serviceabc"
},
"span": {
"action": "query.custom",
"db": {
"instance": "customers",
"statement": "SELECT * FROM product_types WHERE user_id=?",
"type": "sql",
"user": {
"name": "readonly_user"
}
},
"destination": {
"service": {
"name": "postgresql",
"resource": "postgresql",
"type": "db"
}
},
"duration": {
"us": 3781
},
"id": "15aaaaaaaaaaaaaa",
"name": "SELECT FROM product_types",
"start": {
"us": 2830
},
"subtype": "postgresql",
"type": "db.postgresql.query"
},
"timestamp": {
"us": 1496170422281000
},
"trace": {
"id": "85925e55b43f4342aaaaaaaaaaaaaaaa"
},
"transaction": {
"id": "85925e55b43f4342"
}
},
{
"@timestamp": "2017-05-30T18:53:27.154Z",
"agent": {
"name": "elastic-node",
"version": "3.14.0"
},
"ecs": {
"version": "1.12.0"
},
"event": {
"outcome": "unknown"
},
"observer": {
"ephemeral_id": "2f13d8fa-83cd-4356-8123-aabfb47a1808",
"hostname": "goat",
"id": "17ad47dd-5671-4c89-979f-ef4533565ba2",
"type": "apm-server",
"version": "8.0.0"
},
"parent": {
"id": "945254c567a5417e"
},
"processor": {
"event": "span",
"name": "transaction"
},
"service": {
"environment": "staging",
"name": "1234_service-12a3"
},
"span": {
"duration": {
"us": 32592
},
"id": "1aaaaaaaaaaaaaaa",
"name": "GET /api/types",
"start": {
"us": 0
},
"subtype": "external",
"type": "request"
},
"timestamp": {
"us": 1496170407154000
},
"trace": {
"id": "945254c567a5417eaaaaaaaaaaaaaaaa"
},
"transaction": {
"id": "945254c567a5417e"
}
},
{
"@timestamp": "2017-05-30T18:53:27.154Z",
"agent": {
"name": "elastic-node",
"version": "3.14.0"
},
"ecs": {
"version": "1.12.0"
},
"event": {
"outcome": "unknown"
},
"observer": {
"ephemeral_id": "2f13d8fa-83cd-4356-8123-aabfb47a1808",
"hostname": "goat",
"id": "17ad47dd-5671-4c89-979f-ef4533565ba2",
"type": "apm-server",
"version": "8.0.0"
},
"parent": {
"id": "945254c567a5417e"
},
"processor": {
"event": "span",
"name": "transaction"
},
"service": {
"environment": "staging",
"name": "1234_service-12a3"
},
"span": {
"action": "post",
"duration": {
"us": 3564
},
"id": "2aaaaaaaaaaaaaaa",
"name": "GET /api/types",
"start": {
"us": 1845
},
"subtype": "http",
"type": "request"
},
"timestamp": {
"us": 1496170407154000
},
"trace": {
"id": "945254c567a5417eaaaaaaaaaaaaaaaa"
},
"transaction": {
"id": "945254c567a5417e"
}
},
{
"@timestamp": "2017-05-30T18:53:27.154Z",
"agent": {
"name": "elastic-node",
"version": "3.14.0"
},
"child": {
"id": [
"4aaaaaaaaaaaaaaa"
]
},
"ecs": {
"version": "1.12.0"
},
"event": {
"outcome": "unknown"
},
"observer": {
"ephemeral_id": "2f13d8fa-83cd-4356-8123-aabfb47a1808",
"hostname": "goat",
"id": "17ad47dd-5671-4c89-979f-ef4533565ba2",
"type": "apm-server",
"version": "8.0.0"
},
"parent": {
"id": "945254c567a5417e"
},
"processor": {
"event": "span",
"name": "transaction"
},
"service": {
"environment": "staging",
"name": "1234_service-12a3"
},
"span": {
"duration": {
"us": 13980
},
"id": "3aaaaaaaaaaaaaaa",
"name": "GET /api/types",
"start": {
"us": 0
},
"type": "request"
},
"timestamp": {
"us": 1496170407154000
},
"trace": {
"id": "945254c567a5417eaaaaaaaaaaaaaaaa"
},
"transaction": {
"id": "945254c567a5417e"
}
}
]