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MySQL Connector/Node.js 8.0.16 has been released

Dear MySQL users,

MySQL Connector/Node.js is a new Node.js driver for use with the X
DevAPI. This release, v8.0.16, is a maintenance release of the
MySQL Connector/Node.js 8.0 series.

The X DevAPI enables application developers to write code that combines
the strengths of the relational and document models using a modern,
NoSQL-like syntax that does not assume previous experience writing
traditional SQL.

MySQL Connector/Node.js can be downloaded through npm (see for details) or from

To learn more about how to write applications using the X DevAPI, see For more information
about how the X DevAPI is implemented in MySQL Connector/Node.js, and
its usage, see

Please note that the X DevAPI requires at least MySQL Server version
8.0 or higher with the X Plugin enabled. For general documentation
about how to get started using MySQL as a document store, see

Changes in MySQL Connector/Node.js 8.0.16 (2019-04-25, General

X DevAPI Notes

* Connector/Node.js now supports connection attributes as
key-value pairs that application programs can pass to the
server. Connector/Node.js defines a default set of
attributes, which can be disabled or enabled. In addition
to these default attributes, applications can also
provide their own set of custom attributes.

+ Specify connection attributes as a
connection-attributes parameter in a connection
string, or by using the connectionAttributes
property using either a plain JavaScript object or
JSON notation to specify the connection
configuration options.
The connection-attributes parameter value must be
either empty (the same as specifying true), a
Boolean value (true or false to enable or disable
the default attribute set), or a list of zero or
more key=value pair specifiers separated by commas
(to be sent in addition to the default attribute
set). Within a list, a missing key value evaluates
as NULL.
The connectionAttributes property allows passing
user-defined attributes to the application using
either a plain JavaScript object or JSON notation to
specify the connection configuration options. Define
each attribute in a nested object under
connectionAttributes where the property names
matches the attribute names, and the property values
match the attribute values. Unlike
connection-attributes, and while using plain
JavaScript objects or JSON notation, if the
connectionAttributes object contains duplicate keys
then no error is thrown and the last value specified
for a duplicate object key is chosen as the
effective attribute value.
Not sending the default client-defined attributes:
mysqlx.getSession('{ "user": "root", "connectionAttributes": false }')


mysqlx.getSession({ user: 'root', connectionAttributes: { foo: 'bar',
baz: 'qux', quux: '' } })

Application-defined attribute names cannot begin with _
because such names are reserved for internal attributes.
If connection attributes are not specified in a valid
way, an error occurs and the connection attempt fails.
For general information about connection attributes, see
Performance Schema Connection Attribute Tables

Functionality Added or Changed

* Optimized the reuse of existing connections through
client.getSession() by only re-authenticating if

* For X DevAPI, performance for statements that are
executed repeatedly (two or more times) is improved by
using server-side prepared statements for the second and
subsequent executions. This happens internally;
applications need take no action and API behavior should
be the same as previously. For statements that change,
repreparation occurs as needed. Providing different data
values or different offset() or limit() values does not
count as a change. Instead, the new values are passed to
a new invocation of the previously prepared statement.

Bugs Fixed

* Idle pooled connections to MySQL Server were not reused,
and instead new connections had to be recreated. (Bug

* Executing client.close() would not close all associated
connections in the connection pool. (Bug #29428477)

* connectTimeout instead of maxIdleTime determined whether
idle connections in the connection pool were reused
rather than creating new connections. (Bug #29427271)

* Released connections from the connection pool were not
being reset and reused; instead new connections were
being made. (Bug #29392088)

* Date values in documents were converted to empty objects
when inserted into a collection. (Bug #29179767, Bug

* A queueTimeout value other than 0 (infinite) prevented
the acquisition of old released connections from the
connection pool. (Bug #29179372, Bug #93841)

On Behalf of MySQL/ORACLE RE Team
Gipson Pulla