Moving applications to the cloud can introduce challenges like scalability issues due to VM size limitations, I/O bottlenecks due to resource sharing, downtime from hypervisor maintenance, regional outages taking down services, and network latency from distance between devices. These problems stem from how applications access data in the cloud. Database load balancing software provides an abstraction layer between apps and databases that can solve these issues by distributing load, caching queries to reduce I/O, queueing transactions during failovers to prevent downtime, and directing traffic to reduce latency.

1. The Cloud is No White Knight
Why Moving to the Cloud Doesn’t Solve All
Your Uptime and Performance Challenges

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The Promise of the Cloud: Fast deployment,
simple operations, flexible infrastructure, EASE

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The Reality: Moving to the cloud can introduce
shortcomings and inefficiencies that undermine
performance and jeopardize uptime.

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Scalability Challenges – VM Size
Large VMs are expensive and they max out.
Leveraging multiple, smaller VMs means
rewriting apps.
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I/O Limitations
Shared resources create IOPS conflicts.
High utilization configs by the cloud provider
and replication traffic can heighten the problem.
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Hypervisor Challenges
Multi-tenancy stresses the hypervisor.
Downtime results when hypervisors reallocate resources
and cloud providers do maintenance.
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Uptime Challenges
Regional outages take down services.
The database will probably failover – but not the app.
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Network Latency
No proximity guarantees – devices can be many hops apart.
High latency can trigger multiple reconnect attempts, which
might require re-authenticating each time, slowing the app.
5/5

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The Heart of the Problem
Each of these cloud challenges derives from how apps access
data. Apps need data to run – but how they access that data
can encumber or free them.

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Software that sits between applications and
data alleviates these cloud challenges.

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Abstraction Layer
Software that sits between apps and databases provides an
abstraction layer. This software directs traffic into the database in
ways that compensate for cloud shortcomings.

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Solving Scalability
Decoupling apps and databases with database
load balancing software enables automatic
scale out for apps – with no recoding.
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Scalability Details
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 Database load balancing software front-ends the database servers
and aggregates them to look like one big database server.
 It automatically performs read/write split, enabling an application –
with no code changes – to use multiple database servers where it
once talked to just one.
 It distributes reads across all the secondaries in the cluster and
sends all writes to the primary.

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Solving I/O Limitations
Database load balancing software acts as a
buffer between the database and the app as
you solve IOPS challenges.
2/5

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I/O Details
2/5
 Database load balancing software provides connection pooling and
multiplexing, offloading server I/O
 It speeds app times with transparent query response caching, further
reducing I/O loads on the server
 It boosts performance with dynamic SQL query load balancing across
multiple database servers, avoiding I/O bottlenecks

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Solving Hypervisor Issues
Database load balancing software manages
all inbound connection requests and
queries, managing server load.
3/5

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Hypervisor Details
3/5
 After database failover, database load balancing software queues
application retries, avoiding the need for multiple retries and avoiding
app errors.
 Once the change-over is complete, the software drains its queue in a
FIFO manner, preserving data integrity while finalizing transactions.
 To maintain data integrity, in-flight database queries that have already
passed the database load balancing software will fail.

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Solving Uptime
Database failover is not the same as
app-transparent failover.
Database load balancing software queues
transactions during the failover and then drains that
queue to the newly ready primary server.
4/5

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Uptime Details
4/5
 Database load balancing software routes around offline servers during
planned outages for maintenance.
 The software distributes the database load across the other available
database servers.
 It retains control over the entire machine from
powering down through all updates.
 Planned and unplanned outages are
seamless and transparent to users.

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Solving Latency
Database load balancing will hold
connections open during any delays and
server retries, to prevent having to re-
authenticate to databases.
5/5

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Latency Details
 Database load balancing software directs traffic to the fastest-
performing server to maximize application performance
 The software enables app-transparent caching and identifies queries
that are good candidates for caching – no developers needed
 The software enables seamless app failover and zero downtime
maintenance – app performance isn’t slowed by database downtime

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CLEAR THE HAZE
Enable continuous availability and
get to the cloud faster by
abstracting your apps from
databases with database load
balancing software.