The problem we met is that we tried to send this request many times to get data but still get 502 error then(while for the other customerIds, there was no problem yet - we could still get data as normal).
"query" : "SELECT
customer.id,
ad_group_ad.ad.id, ad_group_ad.ad_group,
campaign.id, ad_group_ad.ad.legacy_responsive_display_ad.accent_color, ad_group_ad.ad_strength, ad_group_ad.ad.type, ad_group_ad.ad.legacy_responsive_display_ad.allow_flexible_color, ad_group_ad.ad.added_by_google_ads, ad_group_ad.ad.legacy_responsive_display_ad.business_name, ad_group_ad.ad.call_only_ad.phone_number, ad_group_ad.ad.legacy_responsive_display_ad.call_to_action_text, ad_group_ad.policy_summary, ad_group_ad.ad.final_mobile_urls, ad_group_ad.ad.final_urls, ad_group_ad.ad.tracking_url_template, ad_group_ad.ad.url_custom_parameters, ad_group_ad.ad.expanded_text_ad.description, ad_group_ad.ad.text_ad.description1, ad_group_ad.ad.text_ad.description2, ad_group_ad.ad.device_preference, ad_group_ad.ad.display_url, ad_group_ad.ad.legacy_responsive_display_ad.logo_image, ad_group_ad.ad.legacy_responsive_display_ad.square_logo_image, ad_group_ad.ad.legacy_responsive_display_ad.marketing_image, ad_group_ad.ad.legacy_responsive_display_ad.square_marketing_image, ad_group_ad.ad.expanded_dynamic_search_ad.description, ad_group_ad.ad.expanded_text_ad.description2, ad_group_ad.ad.expanded_text_ad.headline_part3, ad_group_ad.ad.legacy_responsive_display_ad.format_setting, ad_group_ad.ad.gmail_ad.header_image, ad_group_ad.ad.gmail_ad.teaser.logo_image, ad_group_ad.ad.gmail_ad.marketing_image, ad_group_ad.ad.gmail_ad.teaser.business_name, ad_group_ad.ad.gmail_ad.teaser.description, ad_group_ad.ad.gmail_ad.teaser.headline, ad_group_ad.ad.text_ad.headline, ad_group_ad.ad.expanded_text_ad.headline_part1, ad_group_ad.ad.expanded_text_ad.headline_part2, ad_group_ad.ad.image_ad.image_url, ad_group_ad.ad.image_ad.pixel_height, ad_group_ad.ad.image_ad.pixel_width, ad_group_ad.ad.image_ad.mime_type,
ad_group_ad.ad.image_ad.name, ad_group_ad.ad.legacy_responsive_display_ad.long_headline, ad_group_ad.ad.legacy_responsive_display_ad.main_color, ad_group_ad.ad.gmail_ad.marketing_image_display_call_to_action.text, ad_group_ad.ad.gmail_ad.marketing_image_display_call_to_action.text_color, ad_group_ad.ad.gmail_ad.marketing_image_headline, ad_group_ad.ad.gmail_ad.marketing_image_description, ad_group_ad.ad.responsive_display_ad.accent_color, ad_group_ad.ad.responsive_display_ad.allow_flexible_color, ad_group_ad.ad.responsive_display_ad.business_name, ad_group_ad.ad.responsive_display_ad.call_to_action_text, ad_group_ad.ad.responsive_display_ad.descriptions, ad_group_ad.ad.responsive_display_ad.price_prefix, ad_group_ad.ad.responsive_display_ad.promo_text, ad_group_ad.ad.responsive_display_ad.format_setting, ad_group_ad.ad.responsive_display_ad.headlines, ad_group_ad.ad.responsive_display_ad.logo_images, ad_group_ad.ad.responsive_display_ad.square_logo_images, ad_group_ad.ad.responsive_display_ad.long_headline, ad_group_ad.ad.responsive_display_ad.main_color, ad_group_ad.ad.responsive_display_ad.marketing_images, ad_group_ad.ad.responsive_display_ad.square_marketing_images, ad_group_ad.ad.expanded_text_ad.path1, ad_group_ad.ad.expanded_text_ad.path2, ad_group_ad.policy_summary, ad_group_ad.ad.legacy_responsive_display_ad.price_prefix, ad_group_ad.ad.legacy_responsive_display_ad.promo_text, ad_group_ad.ad.responsive_search_ad.descriptions, ad_group_ad.ad.responsive_search_ad.headlines, ad_group_ad.ad.responsive_search_ad.path1, ad_group_ad.ad.responsive_search_ad.path2, ad_group_ad.ad.legacy_responsive_display_ad.short_headline, ad_group_ad.status, ad_group_ad.ad.system_managed_resource_source, ad_group_ad.ad.app_ad.descriptions, ad_group_ad.ad.app_ad.headlines, ad_group_ad.ad.app_ad.html5_media_bundles, ad_group_ad.ad.app_ad.images, ad_group_ad.ad.app_ad.mandatory_ad_text, ad_group_ad.ad.app_ad.youtube_videos FROM ad_group_ad ",
"502. That’s an error.
The server encountered a temporary error and could not complete your request.
Please try again in 30 seconds. That’s all we know."