This change alters the way the MongoDB connects to the various servers in a cluster. Previously, the ConnectionContext constructor currently set up the MongoDB client with credentials for the `admin` and `config` databases, and apparently the client eagerly performs authentication against all databases passed in, rather than doing this lazily as DBs are use.
Instead, the code no longer sets up the credentials for the `config` database and instead only sets up credentials for the `admin` database for authentication and authorization. This works as long as the user specified in the connector configuration can read the `config` database.
Several other changes were made to improve the error handling and reporting when the replica set information cannot be read from the `config` database.
Added more logic to the snapshot reader to better handle errors when reading the list of table names in each database. Now, any errors with a single database (e.g., some of the not-quite-a-database names described in the JIRA issue) will cause the snapshot reader to simply skip that database name and continue on (with proper logging).
This change also quotes all of the database and table names when used in SQL statements.
Change the MySQL connector’s `min.row.count.to.stream.results` configuration property to accept a value of 0, which signifies that all `SELECT COUNT(*) FROM tableA` queries should be skipped and instead all results should be streamed.
MySQL 5.7.7 introduced new behavior for handling XA events in the binlog. See the [MySQL documentation|http://dev.mysql.com/doc/refman/5.7/en/xa-restrictions.html] for details. This PR changes the binlog reader so that `XA …` statements appearing in the binlog are ignored altogether.
These new modules run during the '-Passembly' profile and use the new integration test framework that compares all
output produced by a connector to expected results that were previously recorded and verified. These integration test modules
can be run manually with a simple build of those modules or their parent; only the top-level 'integration-tests' module is run
during the assembly profile during builds of the entire codebase.
The MySQL connector uses several threads, so previously upon connector shutdown these threads were simply cancelled. This is fine for the binlog reader (which can stop at any moment), but is a poor approach for the snapshot as we didn’t always properly release the database resources and also didn’t complete the writing of the DDL history.
With this change, the snapshot reader stops in a very controlled manner, basically by having the 10-step snapshot procedure frequently check whether the reader is to continue working, and to completely avoid thread interruption altogether. And, the snapshot procedure will always clean up its database resources (locks, transactions, etc.), even if the procedure is stopped before completion.
This change also refactors how the snapshot and binlog reader are managed. This is no longer done in the MySqlConnectorTask class (which is busy enough), but rather the logic has been encapsulated in a new `ChainedReader` that makes use of a new `Reader` interface. This makes testing of `ChainedReader` easier, and ensure that `ChainedReader` relies only upon the primary methods of `Reader` rather than upon `AbstractReader`. `ChainedReader` handles multiple readers generically, and ensures that when stopped the readers are all handled correctly and completely process all records, yet avoid accidentally starting a subsequent reader(s) when stopping the previous reader.
Recently, Travis-CI changed the sudo enabled Trusty images that we use in our builds to by-default install and run MySQL 5.6 and Postgres 9.6. This commit stops those services in the `before_install` step of our Travis-CI builds.
The MySQL DDL parser was not properly consuming function declarations. For functions, the parser consumes the entire statement without handline the various expressions within the function declaration, but the parser was not properly finding the end of the statement and instead was continuing to try to consume values beyond the end of the statement.
Specifically, when the parser consumes a `BEGIN`, it looks for a corresponding `END`. However, if it encountered an `END IF`, the `IF` plus any remaining tokens were left on the token stream and unprocessed. This confused the parser, which keep looking for statements and ultimately ended with a `No more content` error.
This case was replicated in integration tests, and the code fixed to properly find the end of the statements.
The Travis-CI builds run the Maven build using the `assembly` profile, and this has been failing quite a bit lately.
The first problem appears to be that the Travis-CI environment recently changed to have port 3306 taken, which means that our build fails to start any Docker containers for MySQL that attempt to use this port. A simple fix is to use different ports for the assembly build.
However, trying to change the port numbers for some of the profiles caused a lot of problems, and to correct these required refactoring how the properties are set. The Docker Maven plugin is now configured with separate properties that are set once (depending upon the profile) to determine the port assignments of the various Docker containers. The Failsafe plugin executions then use these Maven properties when setting the system variables (e.g., `database.host`) needed in the integration tests. This appears to have worked, but it still is a bit fragile. For example, the assembly profile defines several Failsafe executions, and during this profile these should be the only executions run; however, if not all the properties are set properly, the build seems to also run the default Failsafe execution in addition to the other `assembly` profile executions. (I think properties can’t only be defined in the execution, but need to also be defined in the Failsafe configuration.)
The “alternative” MySQL Docker images were removed, since they basically should not provide any different behavior than the `mysql/mysql-server` images we normally used. The extra containers required a lot more resources to run and dramatically increased the complexity of the build.
A few other trivial changes were made.
It also updates EmbeddedEngine to use the Kafka commit callbacks introduced after 0.10 and updates AbstractConnectorTest to better synchronize with the embedded engine
By default the MySQL connector handles `DECIMAL` and `NUMERIC` columns using `java.math.BigDecimal` values and describing them using the `org.apache.kafka.connect.data.Decimal` schema type, which serializes the values to a binary form.
This change adds a configuration option that will keep the default behavior, but will instead allow handling `DECIMAL` adn `NUMERIC` values as Java `double` and a schema type of `FLOAT64`.
Added tests to verify whether the connector is properly restarting in the binlog when previously the connector failed or stopped in the middle of a transaction. The tests showed that the connector is not able to properly start when using or not using GTIDs, since restarting from an arbitrary binlog event causes problems since the TABLE_MAP events for the affected tables are skipped.
The logic was changed significantly to record in the offsets the binlog coordinates at the start of the transaction, which should work whether or not GTIDs are used. Upon restart, the connector may have to re-read the events that were previously processed, but now the offset also includes the number of events that were previously processed so that these can be skipped upon restart.
This has an unforunate side effect since the offsets capture a transaction was completed only when it generates a source record for the subsequent transaction. This is because the connector generates source records (with their offsets) for the binlog events in the transaction before the transaction's commit is seen. And, since no additional source records are produced for the transaction commit, the recorded offsets will show that the prior transaction is complete and that all of the events in the subsequent transaction are to be skipped. Thus, upon restart the connector has to re-read (but ignore) all of the binlog events associated with the completed transaction. This shouldn’t be a problem, and will only slow restarts for very large transactions.
The MySQL connector (or rather the DDL parser used in the connector) improperly assumed a `CHAR` JDBC type (and Avro schema `STRING` type) for MySQL columns of type `BINARY`. This corrects the error.
