--- src/plugins/fts-solr/fts-solr-plugin.h.orig	2019-04-14 15:12:07.694289402 +0200
+++ src/plugins/fts-solr/fts-solr-plugin.h	2019-04-14 14:04:17.213939414 +0200
@@ -12,8 +12,10 @@
 
 struct fts_solr_settings {
 	const char *url, *default_ns_prefix;
+	unsigned int batch_size;
 	bool use_libfts;
 	bool debug;
+	bool no_soft_commit;
 };
 
 struct fts_solr_user {
--- src/plugins/fts-solr/fts-solr-plugin.c.orig	2019-04-14 11:41:03.591782439 +0200
+++ src/plugins/fts-solr/fts-solr-plugin.c	2019-04-14 14:37:46.059433864 +0200
@@ -10,6 +10,8 @@
 #include "fts-solr-plugin.h"
 
 
+#define DEFAULT_SOLR_BATCH_SIZE 1000
+
 const char *fts_solr_plugin_version = DOVECOT_ABI_VERSION;
 struct http_client *solr_http_client = NULL;
 
@@ -37,6 +39,10 @@
 		} else if (str_begins(*tmp, "default_ns=")) {
 			set->default_ns_prefix =
 				p_strdup(user->pool, *tmp + 11);
+		} else if (str_begins(*tmp, "batch_size=")) {
+			set->batch_size = atoi(*tmp + 11);
+		} else if (str_begins(*tmp, "no_soft_commit")) {
+			set->no_soft_commit = TRUE;
 		} else {
 			i_error("fts_solr: Invalid setting: %s", *tmp);
 			return -1;
@@ -46,6 +52,7 @@
 		i_error("fts_solr: url setting missing");
 		return -1;
 	}
+	if (set->batch_size <= 0) set->batch_size = DEFAULT_SOLR_BATCH_SIZE;
 	return 0;
 }
--- src/plugins/fts-solr/fts-backend-solr.c.orig	2019-04-14 13:27:56.694117159 +0200
+++ src/plugins/fts-solr/fts-backend-solr.c	2019-04-14 14:40:12.513938845 +0200
@@ -28,8 +28,6 @@
 #define SOLR_HEADER_LINE_MAX_TRUNC_SIZE 1024
 
 #define SOLR_QUERY_MAX_MAILBOX_COUNT 10
-/* How often to flush indexing request to Solr before beginning a new one. */
-#define SOLR_MAIL_FLUSH_INTERVAL 1000
 
 struct solr_fts_backend {
 	struct fts_backend backend;
@@ -392,6 +390,9 @@
 		(struct solr_fts_backend_update_context *)_ctx;
 	struct solr_fts_backend *backend =
 		(struct solr_fts_backend *)_ctx->backend;
+	struct fts_backend *_backend =
+		(struct solr_fts_backend *)_ctx->backend;
+	struct fts_solr_user *fuser = FTS_SOLR_USER_CONTEXT(_backend->ns->user);
 	struct solr_fts_field *field;
 	const char *str;
 	int ret = _ctx->failed ? -1 : 0;
@@ -404,10 +405,12 @@
 		   visible to the following search */
 		if (ctx->expunges)
 			fts_backend_solr_expunge_flush(ctx);
-		str = t_strdup_printf("<commit softCommit=\"true\" waitSearcher=\"%s\"/>",
+		if(!fuser->set.no_soft_commit) {
+			str = t_strdup_printf("<commit softCommit=\"true\" waitSearcher=\"%s\"/>",
 				      ctx->documents_added ? "true" : "false");
-		if (solr_connection_post(backend->solr_conn, str) < 0)
-			ret = -1;
+			if (solr_connection_post(backend->solr_conn, str) < 0)
+				ret = -1;
+		}
 	}
 
 	str_free(&ctx->cmd);
@@ -494,10 +496,13 @@
 {
 	struct solr_fts_backend *backend =
 		(struct solr_fts_backend *)ctx->ctx.backend;
-
-	if (ctx->mails_since_flush++ >= SOLR_MAIL_FLUSH_INTERVAL) {
+	struct fts_backend *_backend =
+		(struct solr_fts_backend *)ctx->ctx.backend;
+	struct fts_solr_user *fuser = FTS_SOLR_USER_CONTEXT(_backend->ns->user);
+	if (ctx->mails_since_flush++ >= fuser->set.batch_size) {
 		if (fts_backed_solr_build_flush(ctx) < 0)
 			ctx->ctx.failed = TRUE;
+		ctx->mails_since_flush++;
 	}
 	if (ctx->post == NULL) {
 		if (ctx->cmd == NULL)
[root@server02 dovecot-2.3.5.1]#