int Do(CWorkerNodeJobContext& context)
{
context.GetCleanupEventSource()->AddListener(
new CSampleJobCleanupListener("Job-do"));
LOG_POST( context.GetJobKey() + " " + context.GetJobInput());
LOG_POST( "This parameter is read from a config file: " << m_Param);
// 1. Get an input data from the client
// (You can use ASN.1 de-serialization here)
//
CNcbiIstream& is = context.GetIStream();
CNcbiOstream& os = context.GetOStream();
string output_type;
is >> output_type; // could be "doubles" or "html"
LOG_POST( "Output type: " << output_type);
int count;
is >> count;
vector<double> dvec;
dvec.reserve(count);
LOG_POST( "Getting " << count << " doubles from stream...");
for (int i = 0; i < count; ++i) {
if (!is.good()) {
ERR_POST( "Input stream error. Index : " << i );
// If anything bad happened, throw an exception
// and its message will be delivered to the client.
throw runtime_error("Worker node input stream error");
}
// Don't forget to check if shutdown has been requested
if (count % 1000 == 0)
switch (context.GetShutdownLevel()) {
case CNetScheduleAdmin::eShutdownImmediate:
case CNetScheduleAdmin::eDie:
// Either this job is not needed anymore (canceled,
// expired or already executed elsewhere), or the
// server is going down and the job's execution
// should be gracefully (yet urgently) aborted and
// the job returned back to the network queue
// for execution by other worker node instances.
context.ReturnJob();
return 1;
default:
break;
}
double d;
is >> d;
dvec.push_back(d);
}
// 2. Doing some time consuming job here
// Well behaved algorithm checks from time to time if
// immediate shutdown has been requested and gracefully return
// without calling context.CommitJob()
//
for (int i = 0; i < m_Iters; ++i) {
switch (context.GetShutdownLevel()) {
case CNetScheduleAdmin::eShutdownImmediate:
case CNetScheduleAdmin::eDie:
// Either this job is not needed anymore (canceled,
// expired or already executed elsewhere), or the
// server is going down and the job's execution
// should be gracefully (yet urgently) aborted and
// the job returned back to the network queue
// for execution by other worker node instances.
context.ReturnJob();
return 1;
default:
break;
}
context.PutProgressMessage("Iteration " + NStr::IntToString(i+1) +
" from " + NStr::IntToString(m_Iters));
SleepSec(m_SleepSec);
}
sort(dvec.begin(), dvec.end());
// 3. Return the result to the client
// (You can use ASN.1 serialization here)
//
// CNcbiOstream& os = context.GetOStream();
if (output_type == "html")
os << "<html><head><title>"
"Sample Grid Worker Result Page"
"</title></head><body>"
"<p>Sample Grid Worker Result</p>";
else
os << dvec.size() << ' ';
for (int i = 0; i < count; ++i) {
if (!os.good()) {
ERR_POST( "Output stream error. Index : " << i );
throw runtime_error("Worker node output stream error");
}
os << dvec[i] << ' ';
}
if (output_type == "html")
os << "</body></html>";
// 4. Indicate that the job is done and the result
// can be delivered to the client.
//
context.CommitJob();
LOG_POST( "Job " << context.GetJobKey() << " is done.");
return 0;
}
