Path name to the main storage file. The names for supplemental files, including index and lock files, will be computed from this. Flag that indicates whether the storage should be truncated if it already exists. If true, only reads may be executed against the storage. Note that the "pack" operation is not considered a write operation and is still allowed on a read-only filestorage. Maximum allowed size of the storage file. Operations which would cause the size of the storage to exceed the quota will result in a ZODB.FileStorage.FileStorageQuotaError being raised. The name of the storage that the client wants to use. If the ZEO server serves more than one storage, the client selects the storage it wants to use by name. The default name is '1', which is also the default name for the ZEO server. The maximum size of the client cache, in bytes, KB or MB. The storage name. If unspecified, the address of the server will be used as the name. Enables persistent cache files. The string passed here is used to construct the cache filenames. If it is not specified, the client creates a temporary cache that will only be used by the current object. The directory where persistent cache files are stored. By default cache files, if they are persistent, are stored in the current directory. The minimum delay in seconds between attempts to connect to the server, in seconds. Defaults to 5 seconds. The maximum delay in seconds between attempts to connect to the server, in seconds. Defaults to 300 seconds. A boolean indicating whether the constructor should wait for the client to connect to the server and verify the cache before returning. The default is true. A flag indicating whether this should be a read-only storage, defaulting to false (i.e. writing is allowed by default). A flag indicating whether a read-only remote storage should be acceptable as a fallback when no writable storages are available. Defaults to false. At most one of read_only and read_only_fallback should be true. The authentication realm of the server. Some authentication schemes use a realm to identify the logic set of usernames that are accepted by this server.

Target size, in number of objects, of each connection's object cache. The expected maximum number of simultaneously open connections. There is no hard limit (as many connections as are requested will be opened, until system resources are exhausted). Exceeding pool-size connections causes a warning message to be logged, and exceeding twice pool-size connections causes a critical message to be logged. The expected maximum number of connections simultaneously open per version. Target size, in number of objects, of each version connection's object cache. When multidatabases are in use, this is the name given to this database in the collection. The name must be unique across all databases in the collection. The collection must also be given a mapping from its databases' names to their databases, but that cannot be specified in a ZODB config file. Applications using multidatabases typical supply a way to configure the mapping in their own config files, using the "databases" parameter of a DB constructor.