diff --git a/conf/jvm.options b/conf/jvm.options
new file mode 100644
index 0000000..434a362
--- /dev/null
+++ b/conf/jvm.options
@@ -0,0 +1,23 @@
+## JVM configuration
+
+################################################################
+## IMPORTANT: JVM heap size
+################################################################
+##
+## You should always set the min and max JVM heap
+## size to the same value. For example, to set
+## the heap to 4 GB, set:
+##
+## -Xms4g
+## -Xmx4g
+##
+## See https://opensearch.org/docs/opensearch/install/important-settings/
+## for more information
+##
+################################################################
+
+# Xms represents the initial size of total heap space
+# Xmx represents the maximum size of total heap space
+
+-Xms__XMS__
+-Xmx__XMX__
diff --git a/config_panel.toml b/config_panel.toml
new file mode 100644
index 0000000..31bb53e
--- /dev/null
+++ b/config_panel.toml
@@ -0,0 +1,37 @@
+version = "1.0"
+
+[main]
+
+name.en = "OpenSearch configuration"
+name.fr = "Configuration d'OpenSearch"
+
+services = ["__APP__"]
+
+    [main.jvm]
+    name.en = "JVM (Java Virtual Machine) configuration"
+    name.fr = "Configuration de la JVM (machine virtuelle Java)"
+    optional = false
+
+        [main.jvm.xms]
+        ask.en = "Initial heap space"
+        ask.fr = "Espace initial réservé pour le tas (ou « Heap »)"
+        help = """\
+        Indicate a size followed by a unit (either m for megabytes or g for gigabytes) with no space. Examples: \
+         "512m"\
+         "2g"\
+        """
+        type = "string"
+        pattern.regexp = '^(\d+)[mMgG]$'
+        pattern.error = "Please respect the format describe in help text"
+
+        [main.jvm.xmx]
+        ask.en = "Maximum heap space"
+        ask.fr = "Espace maximal pour le tas (ou « Heap »)"
+        help = """\
+        Indicate a size followed by a unit (either m for megabytes or g for gigabytes) with no space. Examples: \
+         "512m"\
+         "2g"\
+        """
+        type = "string"
+        pattern.regexp = '^(\d+)[mMgG]$'
+        pattern.error = "Please respect the format describe in help text"
diff --git a/doc/screenshots/example.jpg b/doc/screenshots/example.jpg
deleted file mode 100644
index a1efa1a..0000000
Binary files a/doc/screenshots/example.jpg and /dev/null differ
diff --git a/scripts/change_url b/scripts/change_url
deleted file mode 100644
index 322641b..0000000
--- a/scripts/change_url
+++ /dev/null
@@ -1,134 +0,0 @@
-#!/bin/bash
-
-#=================================================
-# GENERIC STARTING
-#=================================================
-# IMPORT GENERIC HELPERS
-#=================================================
-
-source _common.sh
-source /usr/share/yunohost/helpers
-
-#=================================================
-# RETRIEVE ARGUMENTS
-#=================================================
-
-old_domain=$YNH_APP_OLD_DOMAIN
-old_path=$YNH_APP_OLD_PATH
-
-new_domain=$YNH_APP_NEW_DOMAIN
-new_path=$YNH_APP_NEW_PATH
-
-app=$YNH_APP_INSTANCE_NAME
-
-#=================================================
-# LOAD SETTINGS
-#=================================================
-ynh_script_progression --message="Loading installation settings..." --weight=1
-
-# Needed for helper "ynh_add_nginx_config"
-final_path=$(ynh_app_setting_get --app=$app --key=final_path)
-
-# Add settings here as needed by your application
-#db_name=$(ynh_app_setting_get --app=$app --key=db_name)
-#db_user=$db_name
-#db_pwd=$(ynh_app_setting_get --app=$app --key=db_pwd)
-
-#=================================================
-# BACKUP BEFORE CHANGE URL THEN ACTIVE TRAP
-#=================================================
-ynh_script_progression --message="Backing up the app before changing its URL (may take a while)..." --weight=1
-
-# Backup the current version of the app
-ynh_backup_before_upgrade
-ynh_clean_setup () {
-	# Remove the new domain config file, the remove script won't do it as it doesn't know yet its location.
-	ynh_secure_remove --file="/etc/nginx/conf.d/$new_domain.d/$app.conf"
-
-	# Restore it if the upgrade fails
-	ynh_restore_upgradebackup
-}
-# Exit if an error occurs during the execution of the script
-ynh_abort_if_errors
-
-#=================================================
-# CHECK WHICH PARTS SHOULD BE CHANGED
-#=================================================
-
-change_domain=0
-if [ "$old_domain" != "$new_domain" ]
-then
-	change_domain=1
-fi
-
-change_path=0
-if [ "$old_path" != "$new_path" ]
-then
-	change_path=1
-fi
-
-#=================================================
-# STANDARD MODIFICATIONS
-#=================================================
-# STOP SYSTEMD SERVICE
-#=================================================
-ynh_script_progression --message="Stopping a systemd service..." --weight=1
-
-ynh_systemd_action --service_name=$app --action="stop" --log_path="/var/log/$app/$app.log"
-
-#=================================================
-# MODIFY URL IN NGINX CONF
-#=================================================
-ynh_script_progression --message="Updating NGINX web server configuration..." --weight=1
-
-nginx_conf_path=/etc/nginx/conf.d/$old_domain.d/$app.conf
-
-# Change the path in the NGINX config file
-if [ $change_path -eq 1 ]
-then
-	# Make a backup of the original NGINX config file if modified
-	ynh_backup_if_checksum_is_different --file="$nginx_conf_path"
-	# Set global variables for NGINX helper
-	domain="$old_domain"
-	path_url="$new_path"
-	# Create a dedicated NGINX config
-	ynh_add_nginx_config
-fi
-
-# Change the domain for NGINX
-if [ $change_domain -eq 1 ]
-then
-	# Delete file checksum for the old conf file location
-	ynh_delete_file_checksum --file="$nginx_conf_path"
-	mv $nginx_conf_path /etc/nginx/conf.d/$new_domain.d/$app.conf
-	# Store file checksum for the new config file location
-	ynh_store_file_checksum --file="/etc/nginx/conf.d/$new_domain.d/$app.conf"
-fi
-
-#=================================================
-# SPECIFIC MODIFICATIONS
-#=================================================
-# ...
-#=================================================
-
-#=================================================
-# GENERIC FINALISATION
-#=================================================
-# START SYSTEMD SERVICE
-#=================================================
-ynh_script_progression --message="Starting a systemd service..." --weight=1
-
-ynh_systemd_action --service_name=$app --action="start" --log_path="/var/log/$app/$app.log"
-
-#=================================================
-# RELOAD NGINX
-#=================================================
-ynh_script_progression --message="Reloading NGINX web server..." --weight=1
-
-ynh_systemd_action --service_name=nginx --action=reload
-
-#=================================================
-# END OF SCRIPT
-#=================================================
-
-ynh_script_progression --message="Change of URL completed for $app" --last
diff --git a/scripts/config b/scripts/config
index b9e79f8..6dbaf67 100644
--- a/scripts/config
+++ b/scripts/config
@@ -1,10 +1,10 @@
 #!/bin/bash
-# In simple cases, you don't need a config script. 
+# In simple cases, you don't need a config script.
 
-# With a simple config_panel.toml, you can write in the app settings, in the 
+# With a simple config_panel.toml, you can write in the app settings, in the
 # upstream config file or replace complete files (logo ...) and restart services.
 
-# The config scripts allows you to go further, to handle specific cases 
+# The config scripts allows you to go further, to handle specific cases
 # (validation of several interdependent fields, specific getter/setter for a value,
 # display dynamic informations or choices, pre-loading of config type .cube... ).
 
@@ -28,72 +28,36 @@ final_path=$(ynh_app_setting_get $app final_path)
 # SPECIFIC GETTERS FOR TOML SHORT KEY
 #=================================================
 
-get__amount() {
-    # Here we can imagine to have an API call to stripe to know the amount of donation during a month
-    local amount = 200
-
-    # It's possible to change some properties of the question by overriding it:
-    if [ $amount -gt 100 ]
-    then
-    cat << EOF
-style: success
-value: $amount
-ask:
-  en: A lot of donation this month: **$amount €**
-EOF
-    else
-    cat << EOF
-style: danger
-value: $amount
-ask:
-  en: Not so much donation this month: $amount €
-EOF
-    fi
+get__xms() {
+    ynh_app_setting_get --app=$app --key=xms
 }
 
-get__prices() {
-    local prices = "$(grep "DONATION\['" "$final_path/settings.py" | sed -r "s@^DONATION\['([^']*)'\]\['([^']*)'\] = '([^']*)'@\1/\2/\3@g" | sed -z 's/\n/,/g;s/,$/\n/')"
-    if [ "$prices" == "," ];
-    then
-        # Return YNH_NULL if you prefer to not return a value at all.
-        echo YNH_NULL
-    else
-        echo $prices
-    fi
+get__xmx() {
+    ynh_app_setting_get --app=$app --key=xmx
 }
 
-
 #=================================================
 # SPECIFIC VALIDATORS FOR TOML SHORT KEYS
 #=================================================
-validate__publishable_key() {
-
-    # We can imagine here we test if the key is really a publisheable key
-    (is_secret_key $publishable_key) &&
-        echo 'This key seems to be a secret key'
-}
 
 #=================================================
 # SPECIFIC SETTERS FOR TOML SHORT KEYS
 #=================================================
-set__prices() {
 
-    #---------------------------------------------
-    # IMPORTANT: setter are trigger only if a change is detected
-    #---------------------------------------------
-    for price in $(echo $prices | sed "s/,/ /"); do
-        frequency=$(echo $price | cut -d/ -f1)
-        currency=$(echo $price | cut -d/ -f2)
-        price_id=$(echo $price | cut -d/ -f3)
-        sed "d/DONATION\['$frequency'\]\['$currency'\]" "$final_path/settings.py"
+regenerate_jvm_options() {
+    ynh_add_config --template="jvm.options" --destination="$final_path/config/jvm.options.d/yunohost.options"
+    chown $app:$app "$final_path/config/jvm.options.d/yunohost.options"
+    chmod 400 "$final_path/config/jvm.options.d/yunohost.options"
+}
 
-        echo "DONATION['$frequency']['$currency'] = '$price_id'" >> "$final_path/settings.py"
-    done
-    
-    #---------------------------------------------
-    # IMPORTANT: to be able to upgrade properly, you have to saved the value in settings too
-    #---------------------------------------------
-    ynh_app_setting_set $app prices $prices
+set__xms() {
+    ynh_app_setting_set --app=$app --key=xms --value=$xms
+    regenerate_jvm_options
+}
+
+set__xmx() {
+    ynh_app_setting_set --app=$app --key=xmx --value=$xmx
+    regenerate_jvm_options
 }
 
 #=================================================
diff --git a/scripts/install b/scripts/install
index 157b1f3..353f352 100755
--- a/scripts/install
+++ b/scripts/install
@@ -41,6 +41,16 @@ ynh_script_progression --message="Finding an available port..." --weight=1
 port=$(ynh_find_port --port=9200)
 ynh_app_setting_set --app=$app --key=port --value=$port
 
+#=================================================
+# DEFAULT VALUES FOR CONFIGURATION
+#=================================================
+
+xms=256m
+ynh_app_setting_set --app=$app --key=xms --value=$xms
+
+xmx=1g
+ynh_app_setting_set --app=$app --key=xmx --value=$xmx
+
 #=================================================
 # INSTALL DEPENDENCIES
 #=================================================
@@ -98,14 +108,15 @@ chmod 700 "/run/$app"
 chown $app:$app "/run/$app"
 
 #=================================================
-# ADD A CONFIGURATION
+# ADD CONFIGURATIONS
 #=================================================
-ynh_script_progression --message="Adding a configuration file..." --weight=1
+ynh_script_progression --message="Adding the configuration files..." --weight=1
 
 ynh_add_config --template="opensearch.yml" --destination="$final_path/config/opensearch.yml"
+ynh_add_config --template="jvm.options" --destination="$final_path/config/jvm.options.d/yunohost.options"
 
-chmod 400 "$final_path/config/opensearch.yml"
-chown $app:$app "$final_path/config/opensearch.yml"
+chmod 400 "$final_path/config/opensearch.yml" "$final_path/config/jvm.options.d/yunohost.options"
+chown $app:$app "$final_path/config/opensearch.yml" "$final_path/config/jvm.options.d/yunohost.options"
 
 #=================================================
 # SETUP SYSTEMD
diff --git a/scripts/upgrade b/scripts/upgrade
index fb9fe3b..98b4e60 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -19,6 +19,8 @@ app=$YNH_APP_INSTANCE_NAME
 final_path=$(ynh_app_setting_get --app=$app --key=final_path)
 datadir=$(ynh_app_setting_get --app=$app --key=datadir)
 port=$(ynh_app_setting_get --app=$app --key=port)
+xms=$(ynh_app_setting_get --app=$app --key=xms)
+xmx=$(ynh_app_setting_get --app=$app --key=xmx)
 
 #=================================================
 # CHECK VERSION
@@ -92,7 +94,7 @@ then
 	ynh_script_progression --message="Upgrading source files..." --weight=20
 
 	# Download, check integrity, uncompress and patch the source from app.src
-	ynh_setup_source --dest_dir="$final_path" --keep="config/opensearch.yml"
+	ynh_setup_source --dest_dir="$final_path" --keep="config/opensearch.yml config/jvm.options.d/yunohost.conf"
 fi
 
 chmod 750 "$final_path"
@@ -112,9 +114,10 @@ ynh_install_app_dependencies $pkg_dependencies
 ynh_script_progression --message="Updating a configuration file..." --weight=1
 
 ynh_add_config --template="opensearch.yml" --destination="$final_path/config/opensearch.yml"
+ynh_add_config --template="jvm.options" --destination="$final_path/config/jvm.options.d/yunohost.options"
 
-chmod 400 "$final_path/config/opensearch.yml"
-chown $app:$app "$final_path/config/opensearch.yml"
+chmod 400 "$final_path/config/opensearch.yml" "$final_path/config/jvm.options.d/yunohost.options"
+chown $app:$app "$final_path/config/opensearch.yml" "$final_path/config/jvm.options.d/yunohost.options"
 
 #=================================================
 # SETUP SYSTEMD