Save the prior dist_stats created during the online setup dag to the backup dir

gstlal-inspiral/bin/gstlal_inspiral_create_prior_diststats

@@ -75,7 +75,7 @@ def parse_command_line():
 	parser.add_option("--coincidence-threshold", metavar = "value", type = "float", default = 0.005, help = "Set the coincidence window in seconds (default = 0.005).  The light-travel time between instruments will be added automatically in the coincidence test.")
 	# FIXME:  default must be identical to gstlal_inspiral's default
 	parser.add_option("--min-instruments", metavar = "count", type = "int", default = 2, help = "Set the minimum number of instruments that must contribute triggers to form a candidate (default = 2).")
-	parser.add_option("--write-likelihood", metavar = "filename", help = "Write merged raw likelihood data to this file.")
+	parser.add_option("--write-likelihood", metavar = "filename", action = "append", help = "Write merged raw likelihood data to this file.")
 	parser.add_option("--instrument", action = "append", help = "Append to a list of instruments to create dist stats for.  List must be whatever instruments you intend to analyze.")
 	parser.add_option("-p", "--background-prior", metavar = "N", default = 1, type = "float", help = "Include an exponential background prior with the maximum bin count = N, default 1")
 	parser.add_option("--df", metavar = "N", default = 40, help = "set the degrees of freedom for the background chisq prior: default 40. You can also use template bandwidth to set this by setting it to 'bandwidth' or the values analytically derived from auto-correlations by setting it to 'analytic'.")
@@ -250,4 +250,5 @@ if options.write_empty_rankingstatpdf:
 
 
 process.set_end_time_now()
-ligolw_utils.write_filename(xmldoc, options.write_likelihood, verbose = options.verbose)
+for filename in options.write_likelihood:
+	ligolw_utils.write_filename(xmldoc, filename, verbose = options.verbose)

gstlal-inspiral/python/dags/layers/inspiral.py

@@ -29,7 +29,7 @@ from lal.utils import CacheEntry
 from ligo.segments import segment
 
 from gstlal import plugins
-from gstlal.datafind import DataType, DataCache
+from gstlal.datafind import DataType, DataCache, DEFAULT_BACKUP_DIR
 from gstlal.dags import Argument, Option
 from gstlal.dags import util as dagutil
 from gstlal.dags.layers import Layer, Node
@@ -513,7 +513,11 @@ def create_prior_layer(config, dag, svd_bank_cache, median_psd_cache, dist_stat_
 			svd_bins=config.svd.bins,
 			root="rank",
 		)
+		backup_cache = None
+
 	else:
+		# assume online operation; create a DIST_STATS cache
+		# and a PRIOR_DIST_STATS in the backup dir
 		prior_cache = DataCache.generate(
 			DataType.DIST_STATS,
 			config.all_ifos,
@@ -521,6 +525,18 @@ def create_prior_layer(config, dag, svd_bank_cache, median_psd_cache, dist_stat_
 			svd_bins=config.svd.bins,
 		)
 
+		backup_cache = DataCache.generate(
+			DataType.PRIOR_DIST_STATS,
+			config.all_ifos,
+			config.span,
+			svd_bins=config.svd.bins,
+			root=DEFAULT_BACKUP_DIR,
+		)
+		backup_dir = os.path.dirname(backup_cache.files[0])
+		if not os.path.exists(backup_dir):
+			os.makedirs(backup_dir)
+		backup_cache = backup_cache.groupby("bin")
+
 	svd_banks = svd_bank_cache.groupby("bin")
 	arguments = [
 		Option("df", prior_df),
@@ -539,7 +555,10 @@ def create_prior_layer(config, dag, svd_bank_cache, median_psd_cache, dist_stat_
 		if prior_df == "bandwidth":
 			inputs += [Option("psd-xml", median_psd_cache.files)]
 
-		outputs = [Option("write-likelihood", prior.files)]
+		output_filenames = prior.files
+		if backup_cache:
+			output_filenames += backup_cache[svd_bin].files
+		outputs = [Option("write-likelihood", output_filenames)]
 		if write_empty_rankingstatpdf:
 			if i == 0:
 				# create an empty rankingstatpdf using the first svd bin's prior file