MongoDB - PHP - MongoCursorException“找不到游标”
我有 2 个集合：A（380 万个文档）和 B（170 万个文档）
我有一个从 shell 运行的 PHP 脚本：
- 大约 60% 的时间循环遍历 A 中的每条记录
- ，它在 B 上执行 findOne （使用_id）
- 创建一个php数组
做了一些基本的数学运算，一旦完成a中所有文档的循环，就
： 4）循环php数组
5）在（1）期间将其插入到集合C中
，我始终得到：PHP Fatal错误：未捕获异常“MongoCursorException”，消息“未找到光标” 最后处理的项目是 3872494 中的#8187。
real 1m25.478s
user 0m0.076s
sys 0m0.064s
再次运行它，代码没有更改，异常在项目#19826 / 3872495 处抛出
real 3m19.144s
user 0m0.120s
sys 0m0.072s
，再次，#8181 / 387249
real 1m31.110s
user 0m0.036s
sys 0m0.048s
是的，我意识到我可以（并且可能应该）捕获例外...但是...为什么它会被抛出？尤其是在数据库中经过的时间/深度如此不同的情况下。
如果有帮助的话，我的设置是 3 节点副本集 (2+arb)。我将辅助设备脱机并尝试仅运行主要设备。结果相同（处理的结果数量和次数不同，但总是抛出 Cursor Not Found 异常）。
I have 2 collections: A (3.8M docs) and B (1.7M docs)
I have a PHP script that I run from the shell that:
- loops over each record in A
- ~60% of the time, it does a findOne on B (using _id)
- does some basic math, creating a php array
once the loop on all docs in a is done:
4) loop over php array
5)upsert into collection C
during (1), I consistently get: PHP Fatal error: Uncaught exception 'MongoCursorException' with message 'Cursor not found'
The last item processed was #8187 of 3872494.
real 1m25.478s
user 0m0.076s
sys 0m0.064s
Running it again, with no change in code, the exception got thrown at item #19826 / 3872495
real 3m19.144s
user 0m0.120s
sys 0m0.072s
And again, #8181 / 387249
real 1m31.110s
user 0m0.036s
sys 0m0.048s
Yes, I realize that I can (and probably should) catch the exception... but... why is it even being thrown? Especially at such different elapsed time/depth into the database.
If it helps, my setup is a 3-node replica set (2+arb). I took the secondary offline and tried with just the primary running. Same results (different number of results processed and times, but always throws the Cursor Not Found exception).
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评论（3）
是的，这绝对是要做的第一件事。异常发生有几十个合理的理由吗？哎呀，当主数据库离线并且无法访问时，您认为会发生什么？
有几个潜在的原因，但让我们直接讨论您看到的错误代码。
MongoDB PHP 驱动程序有两种不同的超时：
您遇到了游标超时。您可以连接到数据库，但您的查询“没有时间”。
可能的修复：
_ids，处理它们，然后标记您已完成此操作。然后获取比上次运行大的下 1000 个_ids，依此类推。我建议#2 以及处理异常。即使这些不能完全解决问题，它也会帮助您隔离和缓解问题。
Yes, this is definitely the first thing to do. There are dozens of legitimate reasons for an exception to happen? Heck what do you think happens when the primary goes off-line and becomes unreachable?
There are a couple of potential reasons, but let's cut straight to the error code you're seeing.
The MongoDB PHP driver has two different timeouts:
You're hitting a cursor timeout. You can connect to the DB, but your query is "running out of time".
Possible fixes:
_idsfrom A, process them and then mark that you have done so. Then get the next 1000_idsgreater than your last run and so on.I would suggest #2 along with handling the exception. Even if these doesn't completely solve the problem it will help you isolate and mitigate the problem.
我知道已经晚了，这可能不是您的解决方案，但您可以尝试使用 immortal()。正如盖茨副总裁指出的那样，此页面描述了该异常。
我想我应该为其他到达此页面的人发布完整的描述，因为 timeout() 和 immortal() 是不同的。 timeout() 设置等待响应的时间。 immortal() 拒绝光标因不活动而死亡。
I know it's late and this may not be your solution but you can try using immortal(). As Gates VP noted, this page describes the exception.
I figured I'd post the entire description for others reaching this page and since timeout() and immortal() are different. timeout() sets the amount of time to wait for a response. immortal() denies the cursor from dying due to inactivity.
这可能是内存限制问题。尝试提供更多内存，看看结果是否有所不同，您可以使用 -d 选项来做到这一点： php -d memory_limit=256M yourscript.php
这是很多文档，听起来您正在制作一个相当大的文档对象数组。还有各种 php 函数，例如 memory_get_usage()，您可以使用它们在运行时分析内存分配以及调试扩展，例如 xdebug 或 zend 提供的功能。
It could be a memory limit issue. Try experimenting with providing more memory and see if your results vary, which you can do with the -d option: php -d memory_limit=256M yourscript.php
That is a lot of documents, and it sounds like you're making a pretty large array of objects. There are also various php functions like memory_get_usage() you can use to profile your memory allocation at runtime as well as debugging extensions like xdebug or what zend provides.