History

George Joseph 5aa5c49413 sorcery/res_pjsip: Refactor for realtime performance There were a number of places in the res_pjsip stack that were getting all endpoints or all aors, and then filtering them locally. A good example is pjsip_options which, on startup, retrieves all endpoints, then the aors for those endpoints, then tests the aors to see if the qualify_frequency is > 0. One issue was that it never did anything with the endpoints other than retrieve the aors so we probably could have skipped a step and just retrieved all aors. But nevermind. This worked reasonably well with local config files but with a realtime backend and thousands of objects, this was a nightmare. The issue really boiled down to the fact that while realtime supports predicates that are passed to the database engine, the non-realtime sorcery backends didn't. They do now. The realtime engines have a scheme for doing simple comparisons. They take in an ast_variable (or list) for matching, and the name of each variable can contain an operator. For instance, a name of "qualify_frequency >" and a value of "0" would create a SQL predicate that looks like "where qualify_frequency > '0'". If there's no operator after the name, the engines add an '=' so a simple name of "qualify_frequency" and a value of "10" would return exact matches. The non-realtime backends decide whether to include an object in a result set by calling ast_sorcery_changeset_create on every object in the internal container. However, ast_sorcery_changeset_create only does exact string matches though so a name of "qualify_frequency >" and a value of "0" returns nothing because the literal "qualify_frequency >" doesn't match any name in the objset set. So, the real task was to create a generic string matcher that can take a left value, operator and a right value and perform the match. To that end, strings.c has a new ast_strings_match(left, operator, right) function. Left and right are the strings to operate on and the operator can be a string containing any of the following: = (or NULL or ""), !=, >, >=, <, <=, like or regex. If the operator is like or regex, the right string should be a %-pattern or a regex expression. If both left and right can be converted to float, then a numeric comparison is performed, otherwise a string comparison is performed. To use this new function on ast_variables, 2 new functions were added to config.c. One that compares 2 ast_variables, and one that compares 2 ast_variable lists. The former is useful when you want to compare 2 ast_variables that happen to be in a list but don't want to traverse the list. The latter will traverse the right list and return true if all the variables in it match the left list. Now, the backends' fields_cmp functions call ast_variable_lists_match instead of ast_sorcery_changeset_create and they can now process the same syntax as the realtime engines. The realtime backend just passes the variable list unaltered to the engine. The only gotcha is that there's no common realtime engine support for regex so that's been noted in the api docs for ast_sorcery_retrieve_by_fields. Only one more change to sorcery was done... A new config flag "allow_unqualified_fetch" was added to reg_sorcery_realtime. "no": ignore fetches if no predicate fields were supplied. "error": same as no but emit an error. (good for testing) "yes": allow (the default); "warn": allow but emit a warning. (good for testing) Now on to res_pjsip... pjsip_options was modified to retrieve aors with qualify_frequency > 0 rather than all endpoints then all aors. Not only was this a big improvement in realtime retrieval but even for config files there's an improvement because we're not going through endpoints anymore. res_pjsip_mwi was modified to retieve only endpoints with something in the mailboxes field instead of all endpoints then testing mailboxes. res_pjsip_registrar_expire was completely refactored. It was retrieving all contacts then setting up scheduler entries to check for expiration. Now, it's a single thread (like keepalive) that periodically retrieves only contacts whose expiration time is < now and deletes them. A new contact_expiration_check_interval was added to global with a default of 30 seconds. Ross Beer reports that with this patch, his Asterisk startup time dropped from around an hour to under 30 seconds. There are still objects that can't be filtered at the database like identifies, transports, and registrations. These are not going to be anywhere near as numerous as endpoints, aors, auths, contacts however. Back to allow_unqualified_fetch. If this is set to yes and you have a very large number of objects in the database, the pjsip CLI commands will attempt to retrive ALL of them if not qualified with a LIKE. Worse, if you type "pjsip show endpoint <tab>" guess what's going to happen? :) Having a cache helps but all the objects will have to be retrieved at least once to fill the cache. Setting allow_unqualified_fetch=no prevents the mass retrieve and should be used on endpoints, auths, aors, and contacts. It should NOT be used for identifies, registrations and transports since these MUST be retrieved in bulk. Example sorcery.conf: [res_pjsip] endpoint=config,pjsip.conf,criteria=type=endpoint endpoint=realtime,ps_endpoints,allow_unqualified_fetch=error ASTERISK-25826 #close Reported-by: Ross Beer Tested-by: Ross Beer Change-Id: Id2691e447db90892890036e663aaf907b2dc1c67		9 years ago
..
cdr	ast-db-manage/cdr/env.py: Don't fail if a config file can't be loaded	11 years ago
config	sorcery/res_pjsip: Refactor for realtime performance	9 years ago
voicemail	alembic: Adjust sippeers, queue_members, and voicemail_messages tables.	11 years ago
README.md	Actually add the database schema management utilities	12 years ago
cdr.ini.sample	alembic: Adjust sippeers, queue_members, and voicemail_messages tables.	11 years ago
config.ini.sample	alembic: Adjust sippeers, queue_members, and voicemail_messages tables.	11 years ago
voicemail.ini.sample	alembic: Adjust sippeers, queue_members, and voicemail_messages tables.	11 years ago

README.md

Asterisk Database Manager

Asterisk includes optional database integration for a variety of features. The purpose of this effort is to assist in managing the database schema for Asterisk database integration.

This is implemented as a set of repositories that contain database schema migrations, using Alembic. The existing repositories include:

config - Tables used for Asterisk realtime configuration
voicemail - Tables used for ODBC_STOARGE of voicemail messages

Alembic uses SQLAlchemy, which has support for many databases.

IMPORTANT NOTE: This is brand new and the initial migrations are still subject to change. Only use this for testing purposes for now.

Example Usage

First, create an ini file that contains database connection details. For help with connection string details, see the SQLAlchemy docs.

$ cp config.ini.sample config.ini
... edit config.ini and change sqlalchemy.url ...

Next, bring the database up to date with the current schema.

$ alembic -c config.ini upgrade head

In the future, as additional database migrations are added, you can run alembic again to migrate the existing tables to the latest schema.

$ alembic -c config.ini upgrade head

The migrations support both upgrading and downgrading. You could go all the way back to where you started with no tables by downgrading back to the base revision.

$ alembic -c config.ini downgrade base

base and head are special revisions. You can refer to specific revisions to upgrade or downgrade to, as well.

$ alembic -c config.ini upgrade 4da0c5f79a9c

Offline Mode

If you would like to just generate the SQL statements that would have been executed, you can use alembic's offline mode.

$ alembic -c config.ini upgrade head --sql

Adding Database Migrations

The best way to learn about how to add additional database migrations is to refer to the Alembic documentation.