react-native start gives me "Watchman error: too many pending cache jobs"

Question

问题

当我创建捆绑包时 - watchman 爬网最初失败并显示“too many pending cache jobs”，这似乎减慢了捆绑过程：

$ react-native start --reset-cache

Loading dependency graph...jest-haste-map: Watchman crawl failed. Retrying once with node crawler.

Usually this happens when watchman isn't running. Create an empty .watchmanconfig file in your project's root folder or initialize a git or hg repository in your project.

Error: Watchman error: too many pending cache jobs. Make sure watchman is running for this project. See https://facebook.github.io/watchman/docs/troubleshooting.html

此外，这些可能是相关的：

我可以通过从手表配置中排除 node_modules 来消除错误
没有错误，打包程序将在 20 秒后启动
由于错误，craw 需要 4 秒，但打包程序会在 4 分钟后启动

背景

预捆绑脚本

我运行这些在捆绑器之前，试图获得更多的稳定性：

watchman watch-del-all
watchman shutdown-server
sudo sysctl -w kern.maxfiles=5242880
sudo sysctl -w kern.maxfilesperproc=524288

Watchman 配置文件

我将我的 .watchconfig 文件设置为额外允许：

{
  "ignore_dirs": [],
  "fsevents_latency": 0.5,
  "fsevents_try_resync": true
}

守望者日志

抓取确实完成，根据完整日志

，几秒钟内

$ tail -f /usr/local/var/run/watchman/coolman-state/log

22:08:24,193: [client=0x7ff4a9686d98:stm=0x7ff4a9b2de00:pid=0] send_error_response: too many pending cache jobs
22:08:24,340: [listener] Watchman 4.9.0 <no build info set> starting up on coolman
22:08:24,341: [listener] path /Users/coolman/project/react-native-app is on filesystem type apfs
22:08:24,342: [listener] root /Users/coolman/project/react-native-app using watcher mechanism fsevents (auto was requested)
22:08:24,344: [listener] file limit is 2560 kern.maxfilesperproc=524288
22:08:24,344: [listener] raised file limit to 524288
22:08:24,345: [listener] launchd: "sock" wasn't present in Sockets
22:08:28,805: [io 0x7f87ba000818 /Users/coolman/project/react-native-app] PERF: {"ru_nvcsw": 1460, "ru_nsignals": 0, "ru_msgrcv": 0, "ru_msgsnd": 0, "ru_inblock": 0, "ru_majflt": 0, "ru_nswap": 0, "ru_minflt": 28103, "ru_ixrss": 0, "ru_maxrss": 115109888, "system_time": 2.9349970000000001, "user_time": 1.327971, "elapsed_time": 4.4614079999999996, "pid": 29414, "ru_idrss": 0, "meta": {"root": {"watcher": "fsevents", "ticks": 2, "number": 1, "case_sensitive": false, "recrawl_count": 0, "path": "/Users/coolman/project/react-native-app"}}, "version": "4.9.0", "ru_oublock": 0, "ru_nivcsw": 2171, "start_time": 1564952904.3444469, "description": "full-crawl"}
22:08:28,805: [io 0x7f87ba000818 /Users/coolman/project/react-native-app] crawl complete

Answer 1

解决方案

将 "content_hash_max_items": 500000 添加到我的 .watchmanconfig 为我解决了这个问题。

解释：

Sounds like you need to tune the metadata cache size(s) for your workload; that error occurs when watchman is attempting to insert more cache entries than are configured.

You can specify larger values in your .watchmanconfig file:

content_hash_max_items is related to the content.sha1hex metadata and defaults to 131072. A related option is content_hash_max_warm_per_settle which defaults to 1024 and which causes up to this many items to be assessed on each settle.

symlink_target_max_items defaults to 32768. This cache is used for readlink in the case that queries ask for the symlink target. This is less likely to be your issue.

I would suggest running find /Users/coolman/project/react-native-app | wc -l to get an upper bound on the number of files currently in your project and use that to size these caches; if you have more files than those defaults then you should raise those cache settings accordingly.

I do not recommend changing the fsevents_latency parameter from the default; can you share more context on what led you to change it?

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