Fault-Tolerant Control of a Distributed Database System

<table>Response time (upper panel) and availability (lower panel) resulting from robust control policy (solid black) and nominal control policy (dotted red) versus (a) decision error <svg height="14.57625" id="M342" style="vertical-align:-2.21957pt" version="1.1" viewbox="0 0 43.606251 14.57625" width="43.606251" xmlns="http://www.w3.org/2000/svg">
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<tspan style="font-size: 12.50px; " x="0" y="0">(</tspan>
<tspan style="font-size: 12.50px; " x="4.1635389" y="0">1</tspan>
<tspan style="font-size: 12.50px; " x="13.190791" y="0">−</tspan>
<tspan style="font-size: 12.50px; " x="24.531122" y="0">𝑐</tspan>
<tspan style="font-size: 12.50px; " x="29.719915" y="0">)</tspan>
</text>
</g>
</svg> and (b) control delay <svg height="14.57625" id="M343" style="vertical-align:-2.21957pt" version="1.1" viewbox="0 0 31.049999 14.57625" width="31.049999" xmlns="http://www.w3.org/2000/svg">
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<tspan style="font-size: 12.50px; " x="0" y="0">(</tspan>
<tspan style="font-size: 12.50px; " x="4.1635389" y="0">1</tspan>
<tspan style="font-size: 12.50px; " x="10.415099" y="0">/</tspan>
<tspan style="font-size: 12.50px; " x="13.890966" y="0">𝛿</tspan>
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Journal of Control Science and Engineering

Fault-Tolerant Control of a Distributed Database System

Figure 10