Documentation draft

.gitignore

@@ -12,3 +12,4 @@ testing.log
 data.fs*
 ZEO_forker*.conf
 .eggs/
+doc/_build

MANIFEST.in

@@ -9,5 +9,6 @@ include log.ini
 
 recursive-include src *
 recursive-include doc *.txt
+recursive-include doc *.rst
 
 global-exclude *.pyc

doc/changelog.rst

+.. include:: ../CHANGES.rst

doc/zeo-client-cache-tracing.txt → doc/client-cache-tracing.rst

+========================
 ZEO Client Cache Tracing
 ========================
 
@@ -11,7 +12,7 @@ ZEO client cache is only used when an object is not in the Zope object
 cache; the ZEO client cache avoids roundtrips to the ZEO server.
 
 Enabling Cache Tracing
-----------------------
+======================
 
 To enable cache tracing, you must use a persistent cache (specify a ``client``
 name), and set the environment variable ZEO_CACHE_TRACE to a non-empty
@@ -32,7 +33,7 @@ transaction comments, access paths, or machine information (such as machine
 name or IP address) are logged.
 
 Analyzing a Cache Trace
------------------------
+=======================
 
 The cache_stats.py command-line tool (``python -m
 ZEO.scripts.cache_stats``) is the first-line tool to analyze a cache
@@ -55,7 +56,7 @@ extension.  It will be read from stdin (assuming uncompressed data) if the
 tracefile argument is '-'.
 
 Simulating Different Cache Sizes
---------------------------------
+================================
 
 Based on a cache trace file, you can make a prediction of how well the cache
 might do with a different cache size.  The cache_simul.py tool runs a simulation of
@@ -122,7 +123,7 @@ strategy's code has been updated to be aware of MVCC, these are not further
 documented here.
 
 Simulation Limitations
-----------------------
+======================
 
 The cache simulation is an approximation, and actual hit rate may be higher
 or lower than the simulated result.  These are some factors that inhibit

doc/client-cache.rst

+================
+ZEO Client Cache
+================
+
+The client cache provides a disk based cache for each ZEO client.  The
+client cache allows reads to be done from local disk rather than by remote
+access to the storage server.
+
+The cache may be persistent or transient.  If the cache is persistent, then
+the cache file is retained for use after process restarts.  A non-
+persistent cache uses a temporary file.
+
+The client cache is managed in a single file, of the specified size.
+
+The life of the cache is as follows:
+
+- The cache file is opened (if it already exists), or created and set to
+  the specified size.
+
+- Cache records are written to the cache file, as transactions commit
+  locally, and as data are loaded from the server.
+
+- Writes are to "the current file position".  This is a pointer that
+  travels around the file, circularly.  After a record is written, the
+  pointer advances to just beyond it.  Objects starting at the current
+  file position are evicted, as needed, to make room for the next record
+  written.
+
+A distinct index file is not created, although indexing structures are
+maintained in memory while a ClientStorage is running.  When a persistent
+client cache file is reopened, these indexing structures are recreated
+by analyzing the file contents.
+
+Persistent cache files are created in the directory named in the ``var``
+argument to the ClientStorage, or if ``var`` is None, in the current
+working directory.  Persistent cache files have names of the form::
+
+    client-storage.zec
+
+where:
+
+client -- the client name, as given by the ClientStorage's ``client``
+          argument
+
+storage -- the storage name, as given by the ClientStorage's ``storage``
+           argument; this is typically a string denoting a small integer,
+           "1" by default
+
+For example, the cache file for client '8881' and storage 'spam' is named
+"8881-spam.zec".

doc/conf.py

+# -*- coding: utf-8 -*-
+#
+# ZEO documentation build configuration file, created by
+# sphinx-quickstart on Thu Oct 18 00:16:24 2012.
+#
+# This file is execfile()d with the current directory set to its containing dir.
+#
+# Note that not all possible configuration values are present in this
+# autogenerated file.
+#
+# All configuration values have a default; values that are commented out
+# serve to show the default.
+
+import sys
+import os
+import pkg_resources
+
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+
+sys.path.insert(0, os.path.abspath('.'))
+sys.path.insert(0, os.path.abspath(".."))
+
+# -- General configuration -----------------------------------------------------
+
+# If your documentation needs a minimal Sphinx version, state it here.
+#needs_sphinx = '1.0'
+
+rqmt = pkg_resources.require('ZEO')[0]
+
+# Add any Sphinx extension module names here, as strings. They can be extensions
+# coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
+extensions = [
+    'sphinx.ext.autodoc',
+    'sphinx.ext.doctest',
+    'sphinx.ext.intersphinx',
+    'sphinx.ext.todo',
+    'sphinx.ext.viewcode',
+    'repoze.sphinx.autointerface',
+]
+
+# Add any paths that contain templates here, relative to this directory.
+templates_path = ['_templates']
+
+# The suffix of source filenames.
+source_suffix = '.rst'
+
+# The encoding of source files.
+#source_encoding = 'utf-8-sig'
+
+# The master toctree document.
+master_doc = 'index'
+
+# General information about the project.
+project = u'ZEO'
+copyright = u'2012, Zope Foundation Contributors'
+
+# The version info for the project you're documenting, acts as replacement for
+# |version| and |release|, also used in various other places throughout the
+# built documents.
+#
+# The short X.Y version.
+version = '%s.%s' % tuple(map(int, rqmt.version.split('.')[:2]))
+# The full version, including alpha/beta/rc tags.
+release = version
+
+# The language for content autogenerated by Sphinx. Refer to documentation
+# for a list of supported languages.
+#language = None
+
+# There are two options for replacing |today|: either, you set today to some
+# non-false value, then it is used:
+#today = ''
+# Else, today_fmt is used as the format for a strftime call.
+#today_fmt = '%B %d, %Y'
+
+# List of patterns, relative to source directory, that match files and
+# directories to ignore when looking for source files.
+exclude_patterns = ['_build']
+
+# The reST default role (used for this markup: `text`) to use for all documents.
+#default_role = None
+
+# If true, '()' will be appended to :func: etc. cross-reference text.
+#add_function_parentheses = True
+
+# If true, the current module name will be prepended to all description
+# unit titles (such as .. function::).
+#add_module_names = True
+
+# If true, sectionauthor and moduleauthor directives will be shown in the
+# output. They are ignored by default.
+#show_authors = False
+
+# The name of the Pygments (syntax highlighting) style to use.
+pygments_style = 'sphinx'
+
+# A list of ignored prefixes for module index sorting.
+#modindex_common_prefix = []
+
+
+# -- Options for HTML output ---------------------------------------------------
+
+# The theme to use for HTML and HTML Help pages.  See the documentation for
+# a list of builtin themes.
+html_theme = 'sphinx_rtd_theme'
+
+# Theme options are theme-specific and customize the look and feel of a theme
+# further.  For a list of options available for each theme, see the
+# documentation.
+#html_theme_options = {}
+
+# Add any paths that contain custom themes here, relative to this directory.
+#html_theme_path = []
+
+# The name for this set of Sphinx documents.  If None, it defaults to
+# "<project> v<release> documentation".
+#html_title = None
+
+# A shorter title for the navigation bar.  Default is the same as html_title.
+#html_short_title = None
+
+# The name of an image file (relative to this directory) to place at the top
+# of the sidebar.
+#html_logo = None
+
+# The name of an image file (within the static path) to use as favicon of the
+# docs.  This file should be a Windows icon file (.ico) being 16x16 or 32x32
+# pixels large.
+#html_favicon = None
+
+# Add any paths that contain custom static files (such as style sheets) here,
+# relative to this directory. They are copied after the builtin static files,
+# so a file named "default.css" will overwrite the builtin "default.css".
+html_static_path = ['_static']
+
+# If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
+# using the given strftime format.
+#html_last_updated_fmt = '%b %d, %Y'
+
+# If true, SmartyPants will be used to convert quotes and dashes to
+# typographically correct entities.
+#html_use_smartypants = True
+
+# Custom sidebar templates, maps document names to template names.
+#html_sidebars = {}
+
+# Additional templates that should be rendered to pages, maps page names to
+# template names.
+#html_additional_pages = {}
+
+# If false, no module index is generated.
+#html_domain_indices = True
+
+# If false, no index is generated.
+#html_use_index = True
+
+# If true, the index is split into individual pages for each letter.
+#html_split_index = False
+
+# If true, links to the reST sources are added to the pages.
+#html_show_sourcelink = True
+
+# If true, "Created using Sphinx" is shown in the HTML footer. Default is True.
+#html_show_sphinx = True
+
+# If true, "(C) Copyright ..." is shown in the HTML footer. Default is True.
+#html_show_copyright = True
+
+# If true, an OpenSearch description file will be output, and all pages will
+# contain a <link> tag referring to it.  The value of this option must be the
+# base URL from which the finished HTML is served.
+#html_use_opensearch = ''
+
+# This is the file name suffix for HTML files (e.g. ".xhtml").
+#html_file_suffix = None
+
+# Output file base name for HTML help builder.
+htmlhelp_basename = 'ZEOdoc'
+
+
+# -- Options for LaTeX output --------------------------------------------------
+
+latex_elements = {
+# The paper size ('letterpaper' or 'a4paper').
+#'papersize': 'letterpaper',
+
+# The font size ('10pt', '11pt' or '12pt').
+#'pointsize': '10pt',
+
+# Additional stuff for the LaTeX preamble.
+#'preamble': '',
+}
+
+# Grouping the document tree into LaTeX files. List of tuples
+# (source start file, target name, title, author, documentclass [howto/manual]).
+latex_documents = [
+  ('index', 'ZEO.tex', u'ZEO Documentation',
+   u'Zope Foundation Contributors', 'manual'),
+]
+
+# The name of an image file (relative to this directory) to place at the top of
+# the title page.
+#latex_logo = None
+
+# For "manual" documents, if this is true, then toplevel headings are parts,
+# not chapters.
+#latex_use_parts = False
+
+# If true, show page references after internal links.
+#latex_show_pagerefs = False
+
+# If true, show URL addresses after external links.
+#latex_show_urls = False
+
+# Documents to append as an appendix to all manuals.
+#latex_appendices = []
+
+# If false, no module index is generated.
+#latex_domain_indices = True
+
+
+# -- Options for manual page output --------------------------------------------
+
+# One entry per manual page. List of tuples
+# (source start file, name, description, authors, manual section).
+man_pages = [
+    ('index', 'btrees', u'ZEO Documentation',
+     [u'Zope Foundation Contributors'], 1)
+]
+
+# If true, show URL addresses after external links.
+#man_show_urls = False
+
+
+# -- Options for Texinfo output ------------------------------------------------
+
+# Grouping the document tree into Texinfo files. List of tuples
+# (source start file, target name, title, author,
+#  dir menu entry, description, category)
+texinfo_documents = [
+  ('index', 'ZEO', u'ZEO Documentation',
+   u'Zope Foundation Contributors', 'ZEO', 'Single-server client-server database server for ZODB',
+   'Miscellaneous'),
+]
+
+# Documents to append as an appendix to all manuals.
+#texinfo_appendices = []
+
+# If false, no module index is generated.
+#texinfo_domain_indices = True
+
+# How to display URL addresses: 'footnote', 'no', or 'inline'.
+#texinfo_show_urls = 'footnote'
+
+
+# Example configuration for intersphinx: refer to the Python standard library.
+intersphinx_mapping = {
+    "python": ('https://docs.python.org/3/', None),
+    "persistent": ('https://persistent.readthedocs.io/en/latest/', None),
+    "ZODB": ("https://zodb-docs.readthedocs.io/en/latest/", None),
+}

doc/index.rst

+==========================================================
+ZEO - Single-server client-server database server for ZODB
+==========================================================
+
+ZEO is a client-server storage for `ZODB <http://www.zodb.org>`_ for
+sharing a single storage among many clients. When you use ZEO, a
+lower-level storage, typically a file storage, is opened in the ZEO
+server process.  Client programs connect to this process using a ZEO
+ClientStorage.  ZEO provides a consistent view of the database to all
+clients.  The ZEO client and server communicate using a custom
+protocol layered on top of TCP.
+
+ZEO can be installed with pip like most python packages:
+
+.. code-block:: bash
+
+    pip install zeo
+
+Some alternatives to ZEO:
+
+- `NEO <http://www.neoppod.org/>`_ is a distributed-server
+  client-server storage.
+
+- `RelStorage <http://relstorage.readthedocs.io/en/latest/>`_
+  leverages the RDBMS servers to provide a client-server storage.
+
+Content
+=======
+
+.. toctree::
+    :maxdepth: 2
+
+    introduction
+    server
+    clients
+    protocol
+    nagios
+    ordering
+    client-cache
+    client-cache-tracing
+    blob-nfs
+    changelog
+    reference
+
+Indices and tables
+==================
+
+* :ref:`genindex`
+* :ref:`modindex`
+* :ref:`search`

doc/introduction.rst

+============
+Introduction
+============
+
+There are several features that affect the behavior of
+ZEO.  This section describes how a few of these features
+work.  Subsequent sections describe how to configure every option.
+
+Client cache
+============
+
+Each ZEO client keeps an on-disk cache of recently used data records
+to avoid fetching those records from the server each time they are
+requested.  It is usually faster to read the objects from disk than it
+is to fetch them over the network.  The cache can also provide
+read-only copies of objects during server outages.
+
+The cache may be persistent or transient. If the cache is persistent,
+then the cache files are retained for use after process restarts. A
+non-persistent cache uses temporary files that are removed when the
+client storage is closed.
+
+The client cache size is configured when the ClientStorage is created.
+The default size is 20MB, but the right size depends entirely on the
+particular database.  Setting the cache size too small can hurt
+performance, but in most cases making it too big just wastes disk
+space.
+
+ZEO uses invalidations for cache consistency.  Every time an object is
+modified, the server sends a message to each client informing it of
+the change.  The client will discard the object from its cache when it
+receives an invalidation. (It's actually a little more complicated,
+but we won't get into that here.)
+
+Each time a client connects to a server, it must verify that its cache
+contents are still valid.  (It did not receive any invalidation
+messages while it was disconnected.)  This involves asking the server
+to replay invalidations it missed. If it's been disconnected too long,
+it discards its cache.
+
+
+Invalidation queue
+==================
+
+The ZEO server keeps a queue of recent invalidation messages in
+memory.  When a client connects to the server, it sends the timestamp
+of the most recent invalidation message it has received.  If that
+message is still in the invalidation queue, then the server sends the
+client all the missing invalidations.
+
+The default size of the invalidation queue is 100.  If the
+invalidation queue is larger, it will be more likely that a client
+that reconnects will be able to verify its cache using the queue.  On
+the other hand, a large queue uses more memory on the server to store
+the message.  Invalidation messages tend to be small, perhaps a few
+hundred bytes each on average; it depends on the number of objects
+modified by a transaction.
+
+You can also provide an invalidation age when configuring the
+server. In this case, if the invalidation queue is too small, but a
+client has been disconnected for a time interval that is less than the
+invalidation age, then invalidations are replayed by iterating over
+the lower-level storage on the server.  If the age is too high, and
+clients are disconnected for a long time, then this can put a lot of
+load on the server.
+
+Transaction timeouts
+====================
+
+A ZEO server can be configured to timeout a transaction if it takes
+too long to complete.  Only a single transaction can commit at a time;
+so if one transaction takes too long, all other clients will be
+delayed waiting for it.  In the extreme, a client can hang during the
+commit process.  If the client hangs, the server will be unable to
+commit other transactions until it restarts.  A well-behaved client
+will not hang, but the server can be configured with a transaction
+timeout to guard against bugs that cause a client to hang.
+
+If any transaction exceeds the timeout threshold, the client's
+connection to the server will be closed and the transaction aborted.
+Once the transaction is aborted, the server can start processing other
+client's requests.  Most transactions should take very little time to
+commit.  The timer begins for a transaction after all the data has
+been sent to the server.  At this point, the cost of commit should be
+dominated by the cost of writing data to disk; it should be unusual
+for a commit to take longer than 1 second.  A transaction timeout of
+30 seconds should tolerate heavy load and slow communications between
+client and server, while guarding against hung servers.
+
+When a transaction times out, the client can be left in an awkward
+position.  If the timeout occurs during the second phase of the two
+phase commit, the client will log a panic message.  This should only
+cause problems if the client transaction involved multiple storages.
+If it did, it is possible that some storages committed the client
+changes and others did not.
+
+Connection management
+=====================
+
+A ZEO client manages its connection to the ZEO server.  If it loses
+the connection, it attempts to reconnect.  While
+it is disconnected, it can satisfy some reads by using its cache.
+
+The client can be configured with multiple server addresses.  In this
+case, it assumes that each server has identical content and will use
+any server that is available.  It is possible to configure the client
+to accept a read-only connection to one of these servers if no
+read-write connection is available.  If it has a read-only connection,
+it will continue to poll for a read-write connection.
+
+If a single address resolves to multiple IPv4 or IPv6 addresses,
+the client will connect to an arbitrary of these addresses.
+
+SSL
+===
+
+ZEO supports the use of SSL connections between servers and clients,
+including certificate authentication.  We're still understanding use
+cases for this, so details of operation may change.

doc/nagios.rst

+.. include:: ../src/ZEO/nagios.rst

src/ZEO/ordering.rst → doc/ordering.rst

@@ -182,7 +182,7 @@ B3
   lastTransaction result in ``sync``.
 
 Implementation notes
-===================
+====================
 
 ZEO 4
 -----
@@ -195,12 +195,12 @@ and, fact that client requests, for a particular client, are
 handled by a single thread on the server, and that all output for a
 client goes through a thread-safe queue.
 
-Invalidations are sent from different threads than clients.  Outgoing
+Invalidations are sent from different threads than clients. Outgoing
 data is queued, however, using Python lists, which are protected by
 the GIL.  This means that the serialization provided though storage
 locks is preserved by the way that server outputs are queued.  **The
 queueing mechanism is in part a consequence of the way asyncore, used
-by ZEO4, works.
+by ZEO4, works.**
 
 In ZEO 4 clients, invalidations and loads are handled by separate
 threads. This means that even though data arive in order, they may not

src/ZEO/protocol.txt → doc/protocol.rst

+==========================================
 ZEO Network Protocol (sans authentication)
 ==========================================
 

doc/reference.rst

+=========
+Reference
+=========
+
+Client & server
+===============
+
+.. autofunction:: ZEO.server
+
+.. autofunction:: ZEO.client
+
+.. autoclass:: ZEO.ClientStorage.ClientStorage
+    :members:
+    :show-inheritance:
+
+.. autofunction:: ZEO.DB
+
+Exceptions
+==========
+
+.. automodule:: ZEO.Exceptions
+    :members:
+    :show-inheritance:

doc/server.rst

+==================
+Running the server
+==================
+
+Typically, the ZEO server is run using the ``runzeo`` script that's
+installed as part of a ZEO installation.  The ``runzeo`` script
+accepts command line options, the most important of which is the
+``-C`` (``--configure``) option.  ZEO servers are best configured
+via configuration files.  The ``runzeo`` script also accepts some
+command-line arguments for ad-hoc configurations, but there's an
+easier way to run an ad-hoc server described below.  For more on
+configuring a ZEO server see `Server configuration`_ below.
+
+Server quick-start/ad-hoc operation
+===================================
+
+You can quickly start a ZEO server from a Python prompt::
+
+  import ZEO
+  address, stop = ZEO.server()
+
+This runs a ZEO server on a dynamic address and using an in-memory
+storage.
+
+We can then create a ZEO client connection using the address
+returned::
+
+  connection = ZEO.connection(address)
+
+This is a ZODB connection for a database opened on a client storage
+instance created on the fly.  This is a shorthand for::
+
+  db = ZEO.DB(address)
+  connection = db.open()
+
+Which is a short-hand for::
+
+  client_storage = ZEO.client(address)
+
+  import ZODB
+  db = ZODB.db(client_storage)
+  connection = db.open()
+
+If you exit the Python process, the storage exits as well, as it's run
+in an in-process thread.
+
+You shut down the server more cleanly by calling the stop function
+returned by the ``ZEO.server`` function.
+
+To have data stored persistently, you can specify a file-storage path
+name using a ``path`` parameter.  If you want blob support, you can
+specify a blob-file directory using the ``blob_dir`` directory.
+
+You can also supply a port to listen on, full storage configuration
+and ZEO server configuration options to the ``ZEO.server``
+function. See it's documentation string for more information.
+
+Server configuration
+====================
+
+The script ``runzeo`` runs the ZEO server.  The server can be
+configured using command-line arguments or a configuration file.  This
+document only describes the configuration file.  Run ``runzeo``
+-h to see the list of command-line arguments.
+
+The configuration file specifies the underlying storage the server
+uses, the address it binds to, and a few other optional parameters.
+An example is::
+
+    <zeo>
+      address zeo.example.com:8090
+    </zeo>
+
+    <filestorage>
+      path /var/tmp/Data.fs
+    </filestorage>
+
+    <eventlog>
+      <logfile>
+        path /var/tmp/zeo.log
+        format %(asctime)s %(message)s
+      </logfile>
+    </eventlog>
+
+The format is similar to the Apache configuration format.  Individual
+settings have a name, 1 or more spaces and a value, as in::
+
+  address zeo.example.com:8090
+
+Settings are grouped into hierarchical sections.
+
+The example above configures a server to use a file storage from
+``/var/tmp/Data.fs``.  The server listens on port ``8090`` of
+``zeo.example.com``.  The ZEO server writes its log file to
+``/var/tmp/zeo.log`` and uses a custom format for each line.  Assuming the
+example configuration it stored in ``zeo.config``, you can run a server by
+typing::
+
+    runzeo -C zeo.config
+
+A configuration file consists of a ``<zeo>`` section and a storage
+section, where the storage section can use any of the valid ZODB
+storage types.  It may also contain an event log configuration.  See
+`ZODB documentation <http://www.zodb.org>`_ for information on
+configuring storages.
+
+The ``zeo`` section must list the address.  All the other keys are
+optional.
+
+address
+        The address at which the server should listen.  This can be in
+        the form 'host:port' to signify a TCP/IP connection or a
+        pathname string to signify a Unix domain socket connection (at
+        least one '/' is required).  A hostname may be a DNS name or a
+        dotted IP address.  If the hostname is omitted, the platform's
+        default behavior is used when binding the listening socket (''
+        is passed to socket.bind() as the hostname portion of the
+        address).
+
+read-only
+        Flag indicating whether the server should operate in read-only
+        mode.  Defaults to false.  Note that even if the server is
+        operating in writable mode, individual storages may still be
+        read-only.  But if the server is in read-only mode, no write
+        operations are allowed, even if the storages are writable.  Note
+        that pack() is considered a read-only operation.
+
+invalidation-queue-size
+        The storage server keeps a queue of the objects modified by the
+        last N transactions, where N == invalidation_queue_size.  This
+        queue is used to support client cache verification when a client
+        disconnects for a short period of time.
+
+invalidation-age
+        The maximum age of a client for which quick-verification
+        invalidations will be provided by iterating over the served
+        storage. This option should only be used if the served storage
+        supports efficient iteration from a starting point near the
+        end of the transaction history (e.g. end of file).
+
+transaction-timeout
+        The maximum amount of time, in seconds, to wait for a
+        transaction to commit after acquiring the storage lock,
+        specified in seconds.  If the transaction takes too long, the
+        client connection will be closed and the transaction aborted.
+
+        This defaults to 30 seconds.
+
+client-conflict-resolution
+        Flag indicating that clients should perform conflict
+        resolution. This option defaults to false.
+
+msgpack
+        Use `msgpack <http://msgpack.org/index.html>`_ to serialize
+        and de-serialize ZEO protocol messages.
+
+        An advantage of using msgpack for ZEO communication is that
+        it's a tiny bit faster and a ZEO server can support Python 2
+        or Python 3 clients (but not both).
+
+        msgpack can also be enabled by setting the ``ZEO_MSGPACK``
+        environment to a non-empty string.
+
+Server SSL configuration
+------------------------
+
+A server can optionally support SSL.  Do do so, include a `ssl`
+subsection of the ZEO section, as in::
+
+    <zeo>
+      address zeo.example.com:8090
+      <ssl>
+        certificate server_certificate.pem
+        key server_certificate_key.pem
+      </ssl>
+    </zeo>
+
+    <filestorage>
+      path /var/tmp/Data.fs
+    </filestorage>
+
+    <eventlog>
+      <logfile>
+        path /var/tmp/zeo.log
+        format %(asctime)s %(message)s
+      </logfile>
+    </eventlog>
+
+The ``ssl`` section has settings:
+
+certificate
+  The path to an SSL certificate file for the server. (required)
+
+key
+  The path to the SSL key file for the server certificate (if not
+  included in certificate file).
+
+password-function
+  The dotted name if an importable function that, when imported, returns
+  the password needed to unlock the key (if the key requires a password.)
+
+authenticate
+  The path to a file or directory containing client certificates
+  to authenticate.  (See the ``cafile`` and ``capath``
+  parameters in the Python documentation for
+  ``ssl.SSLContext.load_verify_locations``.)
+
+  If this setting is used. then certificate authentication is
+  used to authenticate clients.  A client must be configured
+  with one of the certificates supplied using this setting.
+
+  This option assumes that you're using self-signed certificates.
+
+Running the ZEO server as a daemon
+==================================
+
+In an operational setting, you will want to run the ZEO server as a
+daemon process that is restarted when it dies.  ``runzeo`` makes no
+attempt to implement a well behaved daemon. It expects that
+functionality to be provided by a wrapper like `zdaemon
+<https://pypi.python.org/pypi/zdaemon>`_ or `supervisord
+<http://supervisord.org/>`_.
+
+Rotating log files
+==================
+
+``runzeo`` will re-initialize its logging subsystem when it receives a
+SIGUSR2 signal.  If you are using the standard event logger, you
+should first rename the log file and then send the signal to the
+server.  The server will continue writing to the renamed log file
+until it receives the signal.  After it receives the signal, the
+server will create a new file with the old name and write to it.
+
+

doc/zeo-client-cache.txt

-ZEO Client Cache
-
-  The client cache provides a disk based cache for each ZEO client.  The
-  client cache allows reads to be done from local disk rather than by remote
-  access to the storage server.
-
-  The cache may be persistent or transient.  If the cache is persistent, then
-  the cache file is retained for use after process restarts.  A non-
-  persistent cache uses a temporary file.
-
-  The client cache is managed in a single file, of the specified size.
-
-  The life of the cache is as follows:
-
- -  The cache file is opened (if it already exists), or created and set to
-    the specified size.
-
-  - Cache records are written to the cache file, as transactions commit
-    locally, and as data are loaded from the server.
-
-  - Writes are to "the current file position".  This is a pointer that
-    travels around the file, circularly.  After a record is written, the
-    pointer advances to just beyond it.  Objects starting at the current
-    file position are evicted, as needed, to make room for the next record
-    written.
-
-  A distinct index file is not created, although indexing structures are
-  maintained in memory while a ClientStorage is running.  When a persistent
-  client cache file is reopened, these indexing structures are recreated
-  by analyzing the file contents.
-
-  Persistent cache files are created in the directory named in the ``var``
-  argument to the ClientStorage, or if ``var`` is None, in the current
-  working directory.  Persistent cache files have names of the form::
-
-    client-storage.zec
-
-  where:
-
-    client -- the client name, as given by the ClientStorage's ``client``
-              argument
-
-    storage -- the storage name, as given by the ClientStorage's ``storage``
-               argument; this is typically a string denoting a small integer,
-               "1" by default
-
-  For example, the cache file for client '8881' and storage 'spam' is named
-  "8881-spam.zec".

setup.py

@@ -141,6 +141,11 @@ setup(name="ZEO",
               'futures',
               'trollius',
           ],
+          'docs': [
+              'Sphinx',
+              'repoze.sphinx.autointerface',
+              'sphinx_rtd_theme',
+          ],
       },
       install_requires=install_requires,
       zip_safe=False,

src/ZEO/__init__.py

@@ -22,10 +22,16 @@ ZEO is now part of ZODB; ZODB's home on the web is
 """
 
 def client(*args, **kw):
+    """
+    Shortcut for :class:`ZEO.ClientStorage.ClientStorage`.
+    """
     import ZEO.ClientStorage
     return ZEO.ClientStorage.ClientStorage(*args, **kw)
 
 def DB(*args, **kw):
+    """
+    Shortcut for creating a :class:`ZODB.DB` using a ZEO :func:`~ZEO.client`.
+    """
     s = client(*args, **kw)
     try:
         import ZODB

src/ZEO/nagios.rst

+=================
 ZEO Nagios plugin
 =================
 
@@ -33,7 +34,7 @@ If we stop the server, we'll error:
     2
 
 Metrics
--------
+=======
 
 The monitor will optionally output server metric data. There are 2
 kinds of metrics it can output, level and rate metric. If we use the
@@ -103,7 +104,7 @@ other monitors (e.g. that get address data from ZooKeeper). It takes:
     >>> stop()
 
 Multi-storage servers
----------------------
+=====================
 
 A ZEO server can host multiple servers.  (This is a feature that will
 likely be dropped in the future.)  When this is the case, the monitor

tox.ini

 [tox]
 envlist =
-    py27,py34,py35,py36,py37,pypy,pypy3,simple
+    py27,py34,py35,py36,py37,pypy,pypy3,simple,docs
 
 [testenv]
 commands =
@@ -31,3 +31,10 @@ basepython =
 commands =
     python setup.py -q test -q
 deps = {[testenv]deps}
+[testenv:docs]
+basepython =
+    python3.8
+commands =
+    sphinx-build -b html doc doc/_build/html
+extras =
+    docs