Ruby error Net::ReadTimeout
From the Ruby docs: http://ruby-doc.org/stdlib-2.1.2/libdoc/net/http/rdoc/Net/HTTP.html
Number of seconds to wait for one block to be read (via one read(2) call). Any number may be used, including Floats for fractional seconds. If the HTTP object cannot read data in this many seconds, it raises a Net::ReadTimeout exception. The default value is 60 seconds.
What is call? Are the service endpoints different? Are you paging through records? APIs often rate limit callers to prevent DDOS attacks. You can try wrapping your api calls in some retry logic or adding some sleep code.