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Update HA doc

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Christopher Jones 2019-08-14 22:11:54 +10:00
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@ -6925,9 +6925,14 @@ version of the Oracle Client libraries.
If you are using Oracle Client 19c, the latest [Easy Connect Plus][151] syntax
allows the use of multiple hosts or ports, along with optional entries for the
wallet location, the distinguished name of the database server, and even lets
some network configuration options be set. This means that a
[`sqlnet.ora`](#tnsadmin) file is not needed for some common connection
scenarios.
some network configuration options be set. This means that
[`tnsnames.ora`](#tnsadmin) or [`sqlnet.ora`](#tnsadmin) files are not needed
for some further common connection scenarios. For example, if a firewall
terminates idle connections every four minutes, you may decide it is more
efficient to keep connections alive instead of having the overhead of
recreation. Your connection string could be
`"mydbmachine.example.com/orclpdb1?expire_time=3"` to send packets every three
minutes with the [`SQLNET.EXPIRE_TIME`][159] feature.
#### <a name="embedtns"></a> 14.2.2 Embedded Connect Descriptor Strings
@ -7225,28 +7230,32 @@ on each connection.
If you increase the size of the pool, you must [increase the number of
threads](#numberofthreads) used by Node.js.
The growth characteristics of a connection pool are determined by the
Pool attributes [`poolIncrement`](#proppoolpoolincrement),
The growth characteristics of a connection pool are determined by the Pool
attributes [`poolIncrement`](#proppoolpoolincrement),
[`poolMax`](#proppoolpoolmax), [`poolMin`](#proppoolpoolmin) and
[`poolTimeout`](#proppoolpooltimeout). Note that when External
Authentication is used, the pool behavior is different, see
[External Authentication](#extauth).
[`poolTimeout`](#proppoolpooltimeout). Note that when [external
authentication](#extauth) or [heterogeneous pools](#connpoolproxy) are used, the
pool growth behavior is different.
Pool expansion happens when the following are all true: (i)
[`getConnection()`](#getconnectionpool) is called and (ii) all the
currently established connections in the pool are "checked out" by
previous `getConnection()` calls and are in-use by the application,
and (iii) the number of those connections is less than the pool's
`poolMax` setting.
[`pool.getConnection()`](#getconnectionpool) is called and (ii) all the
currently established connections in the pool are "checked out" by previous
`pool.getConnection()` calls and are in-use by the application, and (iii) the
number of those connections is less than the pool's `poolMax` setting.
The Oracle Real-World Performance Group's general recommendation for
client connection pools is for the pool to have a fixed sized. The
values of `poolMin` and `poolMax` should be the same (and
`poolIncrement` equal to zero), and the firewall, [resource
manager][101] or user profile [`IDLE_TIME`][100] should not expire
idle sessions. This avoids connection storms which can decrease
throughput. See [About Optimizing Real-World Performance with Static
Connection Pools][23], which contains details about sizing of pools.
The Oracle Real-World Performance Group's general recommendation for client
connection pools is to use a fixed sized. The values of `poolMin` and `poolMax`
should be the same (and `poolIncrement` equal to zero), and the firewall,
[resource manager][101] or user profile [`IDLE_TIME`][100] should not expire
idle sessions. This avoids connection storms which can decrease throughput.
See [Guideline for Preventing Connection Storms: Use Static Pools][23], which
contains details about sizing of pools. Having a fixed size will guarantee that
the database can handle the upper pool size. For example, if a pool needs to
grow but the database resources are limited, then you may see errors such as
*ORA-28547*. With a fixed pool size, this class of error will occur when the
pool is created, allowing you to change the size before users access the
application. With a dynamically growing pool, the error may occur much later
after the pool has been in use for some time.
The Pool attribute [`stmtCacheSize`](#propconnstmtcachesize) can be
used to set the statement cache size used by connections in the pool,
@ -8426,11 +8435,14 @@ terminating idle connections.
You can configure your OS network settings and Oracle Net (which
handles communication between node-oracledb and the database).
For Oracle Net configuration, a [`tnsnames.ora`](#tnsnames) file can
be used to configure the database service settings such as for
failover using Oracle RAC or a standby database. A
[`ENABLE=BROKEN`][36] option can be used to aid detection of a
terminated remote server.
For Oracle Net configuration, a [`tnsnames.ora`](#tnsnames) file can be used to
configure the database service settings such as for failover using Oracle RAC or
a standby database.
A [`SQLNET.EXPIRE_TIME`][159] or [`ENABLE=BROKEN`][36] option can be used to
prevent firewalls from terminating connections. They can also aid detection of
a terminated remote database server. With Oracle Client 19c, you can use
`EXPIRE_TIME` in the [Easy Connect Plus](#easyconnect) connection string.
A [`sqlnet.ora`][136] file can be used to configure settings like
[`SQLNET.OUTBOUND_CONNECT_TIMEOUT`][33], [`SQLNET.RECV_TIMEOUT`][34]
@ -13980,7 +13992,7 @@ can be asked at [AskTom][158].
[20]: http://docs.libuv.org/en/v1.x/threadpool.html
[21]: https://github.com/libuv/libuv
[22]: https://github.com/oracle/node-oracledb/issues/603#issuecomment-277017313
[23]: https://www.oracle.com/pls/topic/lookup?ctx=dblatest&id=GUID-BC09F045-5D80-4AF5-93F5-FEF0531E0E1D
[23]: https://www.oracle.com/pls/topic/lookup?ctx=dblatest&id=GUID-7DFBA826-7CC0-4D16-B19C-31D168069B54
[24]: https://www.oracle.com/pls/topic/lookup?ctx=dblatest&id=GUID-015CA8C1-2386-4626-855D-CC546DDC1086
[25]: https://www.oracle.com/pls/topic/lookup?ctx=dblatest&id=GUID-661BB906-74D2-4C5D-9C7E-2798F76501B3
[26]: http://www.oracle.com/technetwork/topics/php/php-scalability-ha-twp-128842.pdf
@ -14114,3 +14126,4 @@ can be asked at [AskTom][158].
[156]: http://yum.oracle.com/
[157]: https://livesql.oracle.com/
[158]: https://asktom.oracle.com/
[159]: https://www.oracle.com/pls/topic/lookup?ctx=dblatest&id=GUID-1070805B-0703-457C-8D2E-4EEC26193E5F