By default the parameter server aggregates new values by addition. This is ideal for some algorithms, but not for others. I've made some changes to make aggregation more flexible in commit 5485c6ca6e963b63ab641149b8b77f43f2251dd3. Right now it supports aggregation through:
Addition (adds the existing value and pushed value together, this is still the default option)
Maximum (takes the largest of the existing value and pushed value)
Minimum (takes the smallest of the existing value and pushed value)
Replacement (always replaces existing value with pushed value)
By default the parameter server aggregates new values by addition. This is ideal for some algorithms, but not for others. I've made some changes to make aggregation more flexible in commit 5485c6ca6e963b63ab641149b8b77f43f2251dd3. Right now it supports aggregation through: