Allow configuring seismic store back-off via an environment variable.

native/src/impl/file_sd.cpp

@@ -47,11 +47,13 @@
 #include <SDGenericDataset.h>
 #include <SDUtils.h>
 #include <Constants.h>
+#include <HttpContext.h>
 #else
 #include <SDAPI/SDManager.h>
 #include <SDAPI/SDGenericDataset.h>
 #include <SDAPI/SDUtils.h>
 #include <SDAPI/Constants.h>
+#include <SDAPI/HttpContext.h>
 #endif
 
 /** \cond SSTORE */
@@ -932,6 +934,38 @@ public:
       }
     }
   }
+
+  /**
+   * Configure the exponential backoff used by Seismic Store.
+   * Only expected to be used for debugging.
+   *
+   * * -1 => use defaults.
+   * *  0 => Turn off exponential backoff completely.
+   * * >0 =? Set maximum repeat count.
+   */
+  void setBackoff()
+  {
+    int retries = Environment::getNumericEnv("OPENZGY_SD_BACKOFF", -1);
+    if (retries >= 0) {
+      seismicdrive::ExponentialRetryBackoffPolicy policy;
+      if (retries == 0) {
+        policy.enabled = false;
+      }
+      else {
+        policy.enabled = true;
+        policy.maxRetry = retries;
+        policy.initialWaitingTimeMicroSec = 500 * 1000;
+        policy.maxWaitingTimeMicroSec = 32 * 1000 * 1000;
+      }
+      dataset_->setExponentialRetryBackoffPolicy(&policy);
+      if (SeismicStoreFile::_logger(2, ""))
+      SeismicStoreFile::_logger(2, std::stringstream() << std::boolalpha
+              << "Backoff enabled " << policy.enabled
+              << " retries " << policy.maxRetry
+              << " start " << (float)policy.initialWaitingTimeMicroSec*1.0e-6
+              << " max "   << (float)policy.maxWaitingTimeMicroSec*1.0e-6);
+    }
+  }
 };
 
 SDGenericDatasetWrapper::~SDGenericDatasetWrapper()
@@ -1040,6 +1074,8 @@ SeismicStoreFile::SeismicStoreFile(const std::string& filename, OpenMode mode, c
       dataset->open(seismicdrive::SDDatasetDisposition::OVERWRITE, extra);
       break;
     }
+    if (mode != OpenMode::Closed)
+      datasetwrapper->setBackoff();
   }
   catch (const std::exception& ex) {
     SeismicStoreFile::_logger(1, std::stringstream()