wagtail pathoverflow 添加新的子页面

Question

我开发了一个 wagtail 网站，效果很好。这只是一个简单的博客。我能够在它们下添加博客索引页面和博客文章。最近尝试添加新页面时悬停它会给出错误 PathOverflow at /admin/pages/add/blog/blogpage/8/

下面是完整的回溯。

Environment:


Request Method: POST
Request URL: https://vikatakavi.info/admin/pages/add/blog/blogpage/8/

Django Version: 2.1.5
Python Version: 3.5.2
Installed Applications:
['home',
 'search',
 'wagtail.contrib.forms',
 'wagtail.contrib.redirects',
 'wagtail.embeds',
 'wagtail.sites',
 'wagtail.users',
 'wagtail.snippets',
 'wagtail.documents',
 'wagtail.images',
 'wagtail.search',
 'wagtail.admin',
 'wagtail.core',
 'modelcluster',
 'taggit',
 'django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'django.contrib.sitemaps',
 'blog']
Installed Middleware:
['django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware',
 'django.middleware.security.SecurityMiddleware',
 'wagtail.core.middleware.SiteMiddleware',
 'wagtail.contrib.redirects.middleware.RedirectMiddleware']



Traceback:

File "/home/ubuntu/projects/blogger/env/lib/python3.5/site-packages/django/core/handlers/exception.py" in inner
  34.             response = get_response(request)

File "/home/ubuntu/projects/blogger/env/lib/python3.5/site-packages/django/core/handlers/base.py" in _get_response
  126.                 response = self.process_exception_by_middleware(e, request)

File "/home/ubuntu/projects/blogger/env/lib/python3.5/site-packages/django/core/handlers/base.py" in _get_response
  124.                 response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "/home/ubuntu/projects/blogger/env/lib/python3.5/site-packages/django/views/decorators/cache.py" in _wrapped_view_func
  44.         response = view_func(request, *args, **kwargs)

File "/home/ubuntu/projects/blogger/env/lib/python3.5/site-packages/wagtail/admin/urls/__init__.py" in wrapper
  102.             return view_func(request, *args, **kwargs)

File "/home/ubuntu/projects/blogger/env/lib/python3.5/site-packages/wagtail/admin/decorators.py" in decorated_view
  34.             return view_func(request, *args, **kwargs)

File "/home/ubuntu/projects/blogger/env/lib/python3.5/site-packages/wagtail/admin/views/pages.py" in create
  224.             parent_page.add_child(instance=page)

File "/home/ubuntu/projects/blogger/env/lib/python3.5/site-packages/treebeard/mp_tree.py" in add_child
  1013.         return MP_AddChildHandler(self, **kwargs).process()

File "/home/ubuntu/projects/blogger/env/lib/python3.5/site-packages/treebeard/mp_tree.py" in process
  387.             newobj.path = self.node.get_last_child()._inc_path()

File "/home/ubuntu/projects/blogger/env/lib/python3.5/site-packages/treebeard/mp_tree.py" in _inc_path
  1114.             raise PathOverflow(_("Path Overflow from: '%s'" % (self.path, )))

Exception Type: PathOverflow at /admin/pages/add/blog/blogpage/8/
Exception Value: Path Overflow from: '000100010005ZZZZ'

我对此一无所知。

Answer 1

为了存储页面在页面树中的位置，Wagtail 使用了一种称为Materialized Path 的技术，该技术（在其标准设置中）允许在树中的特定点最多进行 1679615 次插入。看来你已经以某种方式达到了这个限制。 （树中每个点的位置表示为 4 个字符的字母数字代码；错误消息中显示的“ZZZZ”是最高可用代码。）

如果您有超过 160 万篇博文，您就会遇到这个限制，但显然这不太可能。更有可能的是，您编写了一个执行大量插入或页面移动的导入或维护脚本 - 例如，如果您有一个随机重新排序页面的脚本，并且您在一个有 10000 个页面的部分上运行它页面，您将在运行大约 160 次后用完索引号。

如果你真的无法避免达到这个限制，那么你可以通过在启动时运行的地方添加以下代码来将限制增加到 6000 万：

from wagtail.core.models import Page
Page.steplen = 5

但是，这不适用于现有数据库 - 您需要在进行此更改后删除并重新创建数据库 - 这意味着树的最大可能深度从 63 级减少到 50 级。